I cant tell you step by step but im pretty sure all you have to do is take off the door panel, there are several pop out tabs around the panel, either to screws or they are just pull out tabs. once you get the panel off you should have easy access to the handle, which should just clip in or screws into the door.. Im not 100% on this but its what im trying to remember when my door panels got taken off when putting in new door speakers.. The door panel though is very tricky to remove because of the wiring that plugs into the passenger door control panel, and also the door handle latches.. It should be an easy DiY if you have some patients and can remember how to re- assembe everything.. one trick if your not sure if you can remember, is take pictures when you remove everything, then review the pictures when you put it back together..
are you replacing the interior handle or the exterior. ill post the directions for both.
Interior: Take off the one screw behind the chrome handle and just slide the the handle forward a little bit and out. take the clip off carefully and the power connection and your done.
Exterior: Take off the door panel by taking off the one scres behind the chrome handle and the other screw in the door handle to close the door. after removing those screws, take the black mirror cover off, its just clips so just pull on it. After that just take the panel off. after taking the panel off get a socket with and extension and stick it through the holes that are in the door panel, it will line up straight with the handle. after taking the two bolts out the handle should wiggle out fairly easy, be careful not to scratch the paint. also when putting the handle back make sure no wires get in the way of the door handle lock, test this by locking and unlocking with the key on the passenger door, it should turn easy both ways.
There you have it, a little long but should be complete. Good Luck and be careful for the paint.