Complex sentence: Kelly goes to secure supplies from the opportunistic supply sergeant "Crapgame" (Don Rickles), and mortar cover for the initial stage is arranged by a bribe to First Sergeant Mulligan (George Savalas).
Split into simpler sentences: Kelly goes to see an opportunistic supply sergeant nicknamed "Crapgame" (Don Rickles). Mortar cover is arranged by a bribe to First Sergeant Mulligan (George Savalas).