Pre-cut all of your paneling pieces before you glue them on the wall, so you can install them quickly and easily. Dry lay a piece of paneling on the wall, and cut it to fit if necessary. Draw the outline of the piece on the wall with a pencil. Repeat the process for each subsequent piece, and stack them near your installation area for easy access.
Make any necessary cuts around fixtures with the carbide hole saw bit attachment for your drill. For electrical box cutouts, drill through the paneling at the corners of the box after you mark it with a tape measure and pencil. Insert a keyhole saw into one of the holes, and cut from hole to hole to remove the box cutout.
Spread a layer of adhesive onto the wall in the area you drew for your first piece of paneling. Use the notched trowel, and ensure that the adhesive is smoothed completely across the installation surface. Work your way up from the bottom to the top.
Press the panel into place, and use the roller to press the sheet into the glue across the length and width of the panel.