http://brewwiki.win/wiki/Post:....How_to_Install_a_Cat
Installing a cat flap might appear daunting but it's easy to do with the right instructions. Determine how high you would like the cat flap (normally it's at the belly height). Mark this point on your door and then use the included template as a guide when drilling. If you have a kitten, or a young kitten, prop the door open very slightly and gradually allow it to go through. Reward it each time it goes through. Take a measurement of the door A cat flap lets your pet to go in and out of your home at the time that is convenient for