Is it bolt-on, or neck through?-
In either case, you will have to sand/strip whatever finish is there on the back of the neck, and perhaps the back of the headstock to match, or better compliment the rest...
-What's the finish like?- The more crazy the original finish, the more complex the lacquering-and therefore the more expensive to do...
Would ye post a photo so we can see yer axe?_Drac