Locate studs and outline
Firstly, you need to use a stud finder and make sure that the area where you are looking to install a doggie door.
Once you manage to locate all the studs and avoid them, position the place you want to place the doggie door in and then outline the area using either tape, or a pencil.
When marking, remember to point out the areas where you need to drill holes. At the same time, you need to remember to keep a one and a half inch gap above the dogs height on a single flap mount, and a two inch one on a double wall mount.
Image Courtesy: geek.com
Position and drill
Next up you need to place your doggie door in the area that it’s going to be rested in. Then you need to drill in the frame and secure it firmly.
Following that, you need to drill a hole in the area that will be working as the entrance/exit for your dog. You will go about drilling this area out in the same manner that you would drill areas out for a window.
Secure and test
Finally, you can put in all the nuts and screws that came with the doggie door, in order to secure it to the frame.
Once that is done, you can get your dog to test out the door, so that you can check if you need to make any adjustments.
Image Courtesy: clickpets.co.uk