Petsafe Big Cat Flap Guide D'installation page 5

Position the cutting template
1
Cut out the cutting template and tape it to the interior side
of the door, matching the shoulder and centre lines on the
cutting template with the horizontal and vertical lines you
drew on the door.
Important: To maintain the structural integrity of your door,
make sure the cutting template is at least 76.2 mm (3 inches)
from the edge of the door on all sides.
2
Use a pencil to trace the outside of the cutting template,
being careful to connect the corners.
Make sure the cutting line is clearly marked on the door.
5