If your replacement battery doesn't come with a cable installed, follow this step to remove and transfer the old one.

With one hand, firmly secure the outer battery cells.

With your free hand, use the point of a spudger to push on alternating sides of the battery connector to walk it out of its socket.

To install the cable:

Gently push the connector partially into its socket.

Use a spudger to push in the outer edges of the connector until it slides fully into its socket.

Do not push on the cables themselves, as this can easily damage them.