Hello Sic
Here is a pic that might help you. The servo actually drops down in the hole. And you can see that there is a small spot that needs to be cut out for the servo leads to go through. The servo bolts to the cover and then you drop the whole thing in the hole. There is some shim material in one of the packets that is the same color as the cover. This will be used to shim the servo 1/32" away from the cover and allow you to countersink the holes. I will take some better pics today that will show this a little better.

chris