HP Compaq NX4820 Maintenance And Service Manual page 127

Removal and Replacement Procedures
5. Spread the retaining tabs 1 on each side of the memory
module socket to release the memory module. (The right side
of the module rises away from the computer.)
6. Slide the module 2 away from the socket at an angle.
✎
Memory modules are slotted to prevent incorrect installation
into the memory module socket.
Removing the Memory Module
Reverse the above procedure to install a memory module.
5–14 Maintenance and Service Guide