You don't need a do-it-yourself manual to remove a faucet handle. It's usually a simple matter of locating the set screw holding the faucet handle to the valve stem, removing that screw and pulling off the handle. Easy peasy... unless, of course, the faucet handle is stuck by minerals in the water, especially calcium salts, which can virtually fuse the handle to the stem. Don't try to break the bond and remove the faucet handle with a hammer. It won't have much effect, and you'll end up damaging the handle and possibly the faucet. This problem is common enough for plumbing suppliers to have developed a special tool called a faucet handle puller to help replace a shower handle. This tool works for handles with center-set screws. For lever-style handles, a flat bar is a better option.
Wait! Where's the Screw?
If you don't see the screw holding the handle to the faucet stem, it's probably hiding behind a cap. The cap usually displays the manufacturer's logo or a red or blue hot/cold emblem. You can usually pop this off with a flat head screwdriver. Place the screwdriver head between the cap and the faucet and tap it gently with a hammer, and the cap should pop off. If you have a faucet with a lever-style handle, look for a set screw underneath the lever. You'll need a 1/8-inch Allen wrench to remove it.
You don't want to lose this screw down the drain, so it's best to put a small container under the faucet to catch it. These screws have a habit of falling unexpectedly as you loosen them. When that happens, you'll be glad the container is there because you won't have to make a special trip to the hardware store to get another one.
How to Use a Faucet Handle Puller
If the stuck faucet handle won't come off after you've removed the screw holding it, you could try using your screwdriver as a lever to force it off, but this doesn't always work. This is why plumbers carry handle pullers. A faucet handle puller is a corkscrew type mechanism with two long forks. You hook the forks to the back of the handle and set the plunger on the hole from which you removed the set screw. Turn the screw on the faucet handle puller to force the plunger into the hole and against the valve stem, and the handle will inch outward until you can pull it off.
Removing Lever-Style Handles
Lever-style handles don't have a hole in the front, so you can't use a faucet handle puller to remove one of these. Instead of trying to pry it off with a screwdriver, however, you should use a flat bar. Slip the end of the right-angled portion of the bar behind the handle and brace it against the wall, then give the bar a quick, forceful pull to loosen the scale holding the handle to the stem. Reposition the flat bar and do this again. Repeat until the handle is loose enough to pull off.
How to Replace the Shower Handle
If the stuck faucet handle is too old or damaged to reuse, look for a replacement that has the same stem depth and number of ribbings so it will fit. It doesn't have to be from the same manufacturer in order to replace the shower handle. You can often find generic handles that will do the job. Before setting the new handle, it's a good idea to soak the faucet stem with vinegar and leave it for several hours to dissolve any remaining scale. This should prevent the handle from sticking again – at least for several years.