I've been tossing around the idea of creating my own paintgun from a purchased airsoft rifle.  I'd like to use a .68 Automag body in the housing of a French FAMAS (http://world.guns.ru/assault/as21-e.htm) or an HK G36 (http://world.guns.ru/assault/as14-e.htm).  I've never done this sort of detailed modification before, so is there anyone on this forum who would know what to do step by step in order to fit the paintball parts into the airsoft parts?  What type of tools do I need? I know the Automag HK G36 is very possible since Billy Goodman has a picture of it on his website in the 'Replica Paintball Guns' section.