We put this up in our 15 year old daughters room.   The wall was one foot less wide  (11 feet) and 2 inches shorter (8 feet) than the mural so we trimmed at the left side and bottom.  There is convenient graphing lines on reverse to ensure straight line trim.  The reverse side also is numbered to ensure you hang the panels right side up and in the correct order.  Wallpaper paste is supplied (mix powder with water to create gelatinous ooze).  Apply with a stiff brush.  We needed two people to hang the panels and work out air bubbles and places where too much glue had been applied (ie uneven). In the end, it looks exactly as pictured and I couldn't be more impressed with how stunning it looks.