Align the new foot inside the cavity.

Make sure the alignment nub on the foot is lined up with the small hole near the perimeter of the pad.

You may want to use a pencil to lightly mark where the alignment nub is located. Be careful not to scratch the lower case with your pencil.

Lay the foot down while keeping it properly aligned.

Check for proper alignment from the inside of the case. The alignment nub should be slightly visible through the alignment hole.