Complex sentence: The announcement of Lowell George's death appeared in the same Rolling Stone cover featuring Rickie Lee Jones crouching in a black bra and white beret--an issue that would become the largest selling issue in the magazine's history up to that time.
Split into simpler sentences: The announcement of Lowell George's death appeared in the same Rolling Stone cover, which featured Jones crouching in a black bra and white beret. The issue that would become the largest selling issue in the magazine's history up to that time.