Locate the several multi-wire connectors on the board.

These connect several parts of each board together and consist of several different colors of wires. There is also a zip-tie holding the two sets of wires together that you can cut if it is getting in your way.

Disconnect the three plastic connectors from the blue colored boards by pulling them up while wiggling them.

Some force is necessary, it may also help to use the Large Needle Nose Pliers.