Run the magnetic stud finder over the location of the wall in which you have chosen to install the safe. Find two parallel wall studs to secure the safe to. Ensure the wall has at least 6 to 10 inches of depth behind it to accommodate the safe. Measure the dimensions of the safe with your measuring tape, and draw a corresponding outline on the wall with a pencil.
Drill holes at the top corners of your penciled outline and inside the lines as well. Cut a hole in your wall with your saber or keyhole saw to provide the space you need for your wall safe. Trim any unfinished edges with your chisel.
Slide your wall safe into the hole you have cut, and locate predrilled anchor locations within the wall safe. Mark these with your pencil. Remove the safe, and drill holes into the anchor locations.
Attach your wall safe to the studs, placing screws into your predrilled holes.