Piece of cake!
Insert a trim tool or or a slim screwdriver under the usb unit already fitted to the car and gently prize it out. Once you lift it you will be able to get your fingers under it and pull it out along with the cables.
The usb cabling is connected to the bottom and held securely by a plastic clip that you have to fold back to release it. You will need to push down the plastic lock tab that holds it in place. Then you can push the blue plastic retainer back that will release the connector. This bit is fiddly but once you get the idea of how it comes off its straight forward.
Fitting really is the reverse of the above.