Prop the chair such that you can access the bolt securing the seat belt.
Remove the bolt taking care not to lose any of the washers. Unclip the belt from the top of the chair and tuck out
of the way. Disconnect any cables going to airbags / seat heaters in order to remove the seats from the car.
Put the seats out of the way and admire a very bare cabin. Collect any stray pound coins!