And I'm happy to report that the installation of this dog door WAS A BREEZE.I don't understand why I saw so many reviews about how difficult this door was to install. It honestly could not have been easier, and my wife and I were able to install it in about 15-20 minutes. Not only were we able to install it very quickly, but we didn't use a drop of glue, nor did we have to use the zip ties that come in the package. Here's how we did it:1. Separate all the pieces with a flathead screwdriver. Pull the two ball shaped pieces off of the frame of the door, they are meant to be removed.2. Have someone hold up half of the frame against the screen in the location you're looking to install it. The second person should be on the other side of the screen with a box cutter. Use the box cutter to make tiny holes in the screen at all of the inserts on the frame that person 1 is holding. You should also make little holes for all of the pegs that are attached to the frame.3. Grab the other half of the base, and snap it together through the little holes in the screen that you just made. That's it, frame is installed. No glue, no zip ties, and the hold seems to be pretty firm.4. Take the box cutter, and cut the screen out of the inside of the frame. Take that piece of screen and snap into the inner frame piece that you haven't installed yet. Snap the inner-frame into the outer-frame to make the swinging door, and viola, you're done.5. The little balls can be used to lock the door flap if needed.Again, this installation couldn't have been easier. The door works well, and has been handling the impact of my blind, 90 pound lab very well. If you're looking for an easy-to-install dog door, look no further.