While glue is still wet, slowly and gently apply print, working from one side of the board to the other. Use a clean cloth or paper towel to rub down the print as you go. When the print covers the entire board, continue to press and rub to smooth the surface.
(Tip: If you want to try again with another print, wash off the glue and paper from the board before the glue sets, and start with another color copy.)