I have done them before,years ago. My advise is to send them in.
The batteries are special and by the time you buy them and the epoxy you don't save much if anything. you have to cut them apart to get at the battery. you can use PVC pipe of the right size to go back together or make a mold and use Epoxy or casting resin. Good Luck on either way you go, it's a pain
for the little you save. If you get Bull Cry the different outfits usually run specials a couple times a year on rebuilding them. Hope this helps a little.................. Sam