Repeat the process of pressing down the spring plate and slightly threading in the screws to install the remaining two heat sink screws.

Tighten the screws down a little at a time in the same order that you installed them—in an "X" pattern starting at one corner and then crossing to the opposite corner.

Do not over-tighten the screws to avoid damaging the logic board. Just tighten them until they stop against the board.