Fill the holes or dips in all of the walls onto which you plan to install the wallpaper, with spackle. Spread the spackle with a putty knife and run the edge of the putty knife across any filled spots to skim the excess spackle from the surface. Let the spackle dry for 24 hours and sand the spackled spots down to even with the rest of the wall.
Pour wallpaper primer into a paint tray. Roll the primer onto the walls onto which you want to install the wallpaper. Fill in the spaces where the roller wouldn't reach around the edges with a paintbrush.
Cut both the wallpaper that you want to display on the wall and an insulating type of wallpaper, such as cork or jute, into strips four inches longer than the height of the wall.
Fill a paint tray with wallpaper glue. Spread wallpaper glue over the back of the first strip of insulated wallpaper with a paint roller.
Place the first strip of wallpaper on the wall in a corner, lining the edges up with the adjacent wall. Press the wallpaper strip to the wall, starting at the top and working your way down. Roll a wallpaper smoother over the wallpaper strip from top to bottom to work out any bubbles.
Lay the next strip of insulating paper beside the first so that the edges of the strips touch. Line the designs on the wallpaper up as much as possible. If the glue squeezes out between wallpaper strips, use a wet rag to wipe the glue off.
Allow the insulating wallpaper to dry for 72 hours to make sure the wallpaper glue is completely dry. Then, lay the wallpaper that you want to display directly over the insulating wallpaper, using the same application method.