Complex sentence: Much of the material was rumored to be finished the night before while they spent the night drinking 180 proof Vodka and some of the members were still drunk from the night before when they finally arrived at the studio.
Split into simpler sentences: Much of the material was rumored to be finished the night before while they spent the night drinking 180 proof Vodka. Some of the members were still drunk from the night before when they finally arrived at the studio.