Complex sentence: After discussing what they should do and who should do it, Alig injected himself with heroin, cut the legs off the corpse, and threw his legs in a garbage bag then stuffed the rest of him in a box.
Split into simpler sentences: After discussing what they should do and who should do it, Alig injected himself with heroin. He then cut the legs off the corpse, put them in a garbage bag, then stuffed the rest in a box.