HP ProBook 6555b Notebook-PC - Manual (Page 122)

13. Close the cover.
14. Turn the computer upside down on a flat surface.
15. Tighten the 3 keyboard access screws.
16. Replace the batteries.
17. Turn the computer right-side up, and then reconnect external power and external devices.
18. Turn on the computer.
112 Chapter 9 Memory modules