+1, not a difficult job. But a long, tedious and sometimes frustrating one...
An excellent tool that I made up and used for this was a piece of hardwood angled and slotted with a flat file wedged into the slot. Then you simply run the tool up the neck a couple of times. Obviously you're never going to get the same result as if you paid attention to each fret end on their own, but it does get pretty close.
Here's a thorough set of instructions on how to make one.
http://www.projectguitar.com/tut/beveltool.htm
Good luck!
