Complex sentence: Staind has been promoting "Chapter V" by showing it to selected fans on their tour bus and are set to tour with 3 Doors Down across the USA on the coming months to promote the album.
Split into simpler sentences: Staind has been promoting "Chapter V" by allowing selected fans to preview it on their tour bus. The band is set to tour with 3 Doors Down across the United States in the coming months to promote the album.