You don't have to remove your door in order to install a cat door.
I love to get things done and sometimes that requires a few short cuts. So one day I decided to give this project a try without removing the door first.
I used my handy black and decker tool to cut out the hole for the cat door.
Once the hole was cut out, I sanded the edges down using a medium grit sand paper.
This video shows how easy it was.....
I hope this will inspire you to tackle projects you may not have considered.