HP 520 Maintenance And Service Manual page 52

Open the computer as far as possible.
4.
Lift the rear edge of the keyboard and swing it toward you until it rests on the palm rest.
5.
Release the zero insertion force (ZIF) connector (1) to which the keyboard cable is attached, and
6.
disconnect the keyboard cable (2).
Remove the keyboard.
7.
Reverse this procedure to install the keyboard.
44 Chapter 4 Removal and replacement procedures