In message , PeterD
writes
Lift spring tab/contact slightly, and lift that end of battery to
above the base of the holder. Slide battery towards spring tab, past
the retaining tab on the other side. Lift the side opposite the spring
tab/contact and slide battery out.

Reinsert in reverse of the above.
Actually, looks like the plastic tab at the top of the pic hinges like a
latch on a DIMM/SIMM socket to me but...
--
Clint Sharp