Some ribbon cable connectors have a plastic locking tab around them. These are often used in large game consoles and mice.

Use a spudger to gently push up on alternating sides of the plastic tab until it clicks up into its unlocked position.

Don't push the tab too hard or too far, otherwise it may come completely off the connector.

Once the tab is unlocked, you can gently pull the cable straight out of its socket.

The cable should be able to slide in and out of the socket with little to no force. If you feel resistance, the tab may not be fully unlocked.

During reassembly, insert the cable into its socket and use the flat end of a spudger to push the tab down into its locked position.