thank you the community ! I decided to make a little hole with a cutter.
The center of the screw is exactly at 10 mm from the center of the foot (see photo in the tuto), on the line between the centers of the two feet. I had not this information so I was two mm too far.
My hole is not very well done but it is very easy tu cut this white plastic. And i’m not often looking at the back of my trackpad