Managed to get the bumper off without removing the wheels by using some long reach bent nose pliers to get the three plastic rivets out that hold the bumper onto the rear wheel arch liners.
Used the pliers to pull the centre pins from the rivets. Used you fingers to feel the pliers onto the pin and just pull it out
Then stick a woodscrew into the hole in the rivet. You can screw it in by hand, use the pliers if needed to screw it in.
Then pull the woodscrew with the pliers and out they come.
If you have pdc do disconnect the PDC wire from the module and pass the cable and grommet out into the bumper void.
A you have then is to unclip the two number plate light connectors.