HP ProBook 4535s Service Manual page 77

Remove the power button board:
1. Position the top cover upside-down with the front toward you.
2. Remove the two Phillips PM2.0×4.0 screws (1) that secure the board to the top cover.
3. Lift the board up at an angle (2), and then remove it from the top cover (3).
Reverse this procedure to install the power button board.
Component replacement procedures 69