Complex sentence: Frankie Banali of Quiet Riot filled in as drummer for the remainder of the tour, then Brett Bradshaw became Faster Pussycat's new long-term drummer.
Split into simpler sentences: Frankie Banali of Quiet Riot filled in as their drummer for the remainder of the tour. After finishing the tour, Brett Bradshaw became Faster Pussycat's new long-term drummer.