The carpet is easy to take out. It is quite heavy as it is rubber backed and has a further backing that is shaped to fit the corrugated floor.
I laid it flat on the patio and sprayed it liberally with Comma Hyper Clean degreaser, and left it for a while to soak in.
Then I folded it over an old garden table and attacked it with the pressure washer. It was unbelievable how much muck came out. After it had drip dryed it was good as new.
The front and back floor carpets are next in line.

Bob