First, determine if the frets are worn enough to justify a refret job. Moderately worn frets can usually be levelled and recrowned, while frets that look like silver painted-on strips can not. You'll have to use your judgement here. General rule: if the fret is wider than it is high, it can't be recrowned.

	Frets are supposed to have rounded tops. When you fret a string, it should only contact one point on the fret: the center of the top.
	If the fret top starts looking flat, the string won't contact a single point. It will clatter and buzz. You don't want this. Your customer doesn't want this. This needs to be fixed. Now. By you.
	If there's enough metal left, you can recrown what's there. The hard way: use a small triangular file, and nick up the fingerboard. The easy way: use a fret crowning file like the one shown here.

Part 1 - Yanking Out the Old Frets

There are only a few ways to pull frets, and any of them are apt to pull up large chips of finish and/or wood with each fret. Practice up on your divot-filling ahead of time - you don't want to hand a customer's guitar to him with the fingerboard covered with stickers. (Ok, maybe a blind customer wouldn't say anything. Don't count on getting a lot of those.)

	This a new, untouched fret slot. This is what the new fret (or, more accurately, the new fret tang) gets pounded into at the factory. You'll never see a slot like this unless you buy a new unfretted neck.
	A new fret seated in its new slot. No gaps, no space between the fret and the fingerboard. So far, so good.
	The same fret being pulled out. Notice the fingerboard (or laquer) lifting at the edges of the slot. It's getting messy now, isn't it? Scared yet? Don't worry, I'm right here ;o)
	Here's the slot (what's left of it) after pulling the fret -- what you get to pound frets into. Think a fret will stay pounded down in this chasm? This is where you start thinking about glueing the new frets in.

If the old frets have only been hammered or pressed in, a child could remove them.
Side note: Children are surprisingly good at it. If you or someone you know happens to run a day care center, a few old guitar necks and fret-pulling pliers are good things to have around. A child is also handy for various repairs inside an acoustic guitar body, such as glueing loose braces, installing endpin jacks, etc.

You need a special end-cutting pliers to pull frets. Buy a small pair at a hardware store and grind the cutting face down, or buy some expensive ones pre-ground (Stewart- MacDonald has them).

	The jaws of commonly-available end-cutting pliers are too blunt to get under the fret edges. Or, more accurately, they're not ground the right way for pulling frets. We can fix that.
	Use a belt sander, a grinder, or (gasp) a file to flatten the outer cutting surface. You want thin.   Note: don't use these for general cutting; the edge will be too delicate.

	So... you've ground your pliers. Carefully work them under one end of a fret and gently squeeze. A slight rocking motion (with the pliers; not with your body) sometimes helps. Work your way across the fret.
	As the fret comes loose, resist the temptation to jerk it out of the slot. The more vigorous you are, the more damage you'll do to the slot. Take your time. Remember, you're charging by the hour.

Note: If some chips break loose (I mean, when some chips break loose) when the fret comes out, grab your trusty superglue and glue them back in immediately. It's handier to do this now than to patch the little divots with something else later.

Note: If it turns out the frets were glued in (you'll know if they were, by the large chunks of wood stuck to each fret as it comes out), you'll have to heat each one with a soldering iron as you're lifting it out. Not too much heat, or you'll burn the fingerboard or melt the binding on a bound neck. (This is something to think about when you're glueing frets in. Hopefully, you won't be the one to fight them out when they get worn down. If you are, recommend replacing the neck.)

Another way to remove frets: drive them out of the slots sideways. Make a small ding at one end of the fret, grab your hammer & center punch, set the tip of the punch in the ding, and start pounding! (Kids like to do this, too, but they seem to scar up the sides of the neck quite a bit.)

Part 2 - Installing New Frets
So... you're standing there with the fret wire you just ordered (in some bizzarre size no other customer will want), looking at these hideously deformed slots. The customer expects the guitar to look and play like it did when it left the factory. Depressing, isn't it? Well, that's why you're doing this -- the challenge. Also the money.

First: The slots have to be narrower than the widest part of the new fret wire, or the chasm will still be visible. This would be bad. If the new wire falls completely into the slot, we need to pause right here. Fill all twenty-one (or twenty-two, or twenty-four) slots with a material of your choice. Ideally, this would be something wood-like in density, hardness, and appearance. My personal preference: wood. If you don't have any suitable wood scraps, plastic wood is fine. Most of the filler won't be seen, anyway. Real purists wouldn't approve, but they're not here, are they?
Level off the whole mess with a sanding block after the glue/plastic wood has set. Then you'll have to recut all the slots as close to factory specs as you can. The slots should ideally be a couple thousandths of an inch wider than the tang of your new wire, but there's actually a lot of leeway here. Your tolerances: wider than the fret tang but narrower than the fret crown.

Second: Cut a two-inch piece of your new wire and test the fit in the slots.
If it's snug enough that you have to press or pound the fret in, great! You lucked out. If the fret wobbles a bit, you'll have to decide on a glue and glue your new frets in. Most popular glue: epoxy. My personal choice: superglue gel. Reason: it sets fast.

Third: Bend the fret wire to the radius of the fingerboard. This is next to impossible to do by hand, as you'll wind up with irregularly-bent, twisted frets. I recommend Stewart-MacDonald's fret bender, which will give you regularly-bent, twisted frets in a fraction of the time. Much more visually pleasing -- and for only $80.00!
Note: Bending the fret wire to match the fingerboard radius is crucial if no glue is used. If you're glueing the frets in, however, it's a time-consuming extra step. The glue will make up for a lot of imperfections.

Fourth: Cut enough two-inch pieces of wire for all the slots, and press/ pound/glue them in. Clean off any excess glue.

Fifth: Cut off the excess wire flush with the fingerboard edge. The closer you get to being flush here, the less you have to file in step six.

Sixth: File off the jagged fret ends. Be careful not to mar the finish on the neck.

Seventh: Level the new frets. My method: color the tops with a magic marker, and file away until you see silver on each one. Then stop.

Eighth: Recrown. Starting to seem like a lot of work? Wait... you're probably doing all this in one shot, aren't you? I should have mentioned that I usually spread a job like this over several days.

Clean up the fingerboard, string up the guitar, and pray for improvement in the way it plays. If not, start preparing your list of other things to blame (see Complaints). The customer, after paying $30-$50 for a level & recrown or $100-$200 for a refret, will expect the guitar to play noticeably better.