Complex sentence: By the time "Thank You" was finally released in 1995, the band was not enthusiastic about supporting the album, and much of the promotional work was done solely by Simon Le Bon and Warren Cuccurullo.
Split into simpler sentences: By the time "Thank You" finally appeared in 1995, the band no longer felt enthusiastic about supporting it. Much of the promotional work was done solely by Simon Le Bon and Warren Cuccurullo.