Use the point of a spudger to push on alternating sides of the CMOS connector to "walk" it out of its socket.

It may take a lot of alternating before the connector comes out. Be patient, and don't pull on the cables.

To reconnect the cable, align the connector and use a spudger or clean fingernail to push it fully into the socket.

Don't push on the cables themselves, or you may damage the connector.

Slide the I/O board out from edge of the laptop to remove it.

The CMOS battery was also removed with the I/O board in this photo. It is held on with a small amount of adhesive. It is not necessary to remove the CMOS battery for this repair.