Compaq 470022-515 - Evo - D300 Hardware Reference Manual page 45

Hardware Reference Guide
b. Slide the replacement battery into position, positive side up.
The battery holder automatically secures the battery in the proper
position.
Type 2
a. To release the battery from its holder, squeeze the metal
clamp that extends above one edge of the battery.
b. When the battery pops up, lift it out.
Removing a Coin Cell Battery (Type 2)
Battery Replacement
C-3