That's the great thing about plastic mastic guns, you can just cut them up. >-< for real though, why do this? why not just put yours for sale and buy a new one in 27/26. Why would you want to chop your gun up?
SHTF vs TEOTWAWKI you ask? SHTF, just some crap on the ceiling and walls, TEOTWAWKI end of the world as we know it. Orignally made by 9mm/®™©