Get a full size toy or airsoft pistol (preferably a revolver), get a episode 2 or 3 anakin skywalker electronic lightsaber, a few small sheets of sintra, various assorted tools, primer, rub n buff, aluminum color paint, dark gray paint, plastic epoxy, caulk, a few sheets of reasonably thick wood, a saber saw (or if you cant afford one, a hand saw), a hairdryer, and a brain.
Cut the lightsaber just at the blade emitter, and throw the blade emitter away, leaving you just a hollow shaft. put the revolver in the shaft, and stick in with plastic epoxy, fill gap with caulk, sand.
take sheets of sintra, heat with a hair dryer on hot for about 5 minutes, to get it floppy, then curl into the shape of a cone, cut the tip off, leaving a hole. Glue to the end of the lightsaber opposite the gun, caulk and sand.
cut out a boba fett stock template (found here:
http://www.propaholics.wolfchasers.c...ev%20Ae121.gif) by printing it out and cutting it with scissors. outline it onto your sheet of wood, then cut it out with a saber saw or hand saw, then sand. measure the width of the end of the stock thumbhole branch things, then cut those size holes in the grip of the pistol. Stick it in there, fill with epoxy, let dry, cover with caulk, and sand.
add a scope (however you want), some greeblies, then paint it however you want (there are a million weathering tutorials) and viola, you have yourself a passable EE-3. feel free to mess around with this recipe however you want, it's just a rough draft