How to install electronic and sliding glass pet doors
Pet door installation is a moderately difficult task that requires several household tools: a hammer, jigsaw, screwdriver, electric drill, and pencil.
One pet's door is another pet's eyehole, so it's a good idea to measure your dog before you go shopping for electronic pet doors. Follow the two-inch rule: the width of the pet door should be two inches wider than your pet and two inches taller than the distance from the pet's shoulders to its chest, i.e. just behind its front legs.
Pet doors are often installed at the bottom of people doors, but some pet owners choose to install them in a wall next to an existing door. Convenience and safety should be your primary criteria. If you're installing an electronic pet door, you'll need to locate it near an electrical outlet.
If you're installing a pet door in an existing door, it may be an easier job if you first remove the door from its hinges. If the pet door you purchased came with a template, use the template and a pencil to mark out the intended location. The bottom edge of the pet door should be at roughly the same level as your pet's chest (again, that means just behind its front legs).
After you've traced the inner edge of the template, mark where the screws for the outer hardware should go, and use an appropriately sized drill bit to drill pilot holes. Next, cut out the opening for the door. To make this part of the automatic pet door installation easier, you could start by drilling a hole in each of the four corners, and then proceed to cut along the pencil line with the jigsaw.
Once you've finished cutting, the outer frame of the pet door should fit flush with the interior door surface. If not, you can use pliers to snap off horizontal and vertical "break off levels" by bending the frame inward. When the outer frame is flush, insert the inner frame and flap. Insert and tighten the screws while holding the electronic or magnetic pet door in place (metal doors will require sheet metal screws).
With electronic pet doors, the final installation step will be attaching the power cord and plugging it into an outlet. Electronic and magnetic pet doors also require the use of a collar key that your pet(s) will need to wear.
Sliding glass pet doors are the exception to these installation procedures. A sliding glass pet door can simply be installed within the glass or screen track of an existing door. In-glass pet doors, however, typically require professional installation.