Here are some more pics. If you just need access to the lumar support bellows you may be able to get away with just removing the inner backrest cushion. There is a zip just where the backrest meets the seat cushion, if you can tilt the seat far enough forward or back so you can get at it, the rest can be done without dismantling the seat. It is hooked onto plastic hooks in the middle of the seat and on to steel hooks at the top - tricky to remove.
The rest of the back rest foam and leather may need more dismantling. The trickiest part was the steel hoops (?) that secure it to steel wire secured to the backrest frame. I didnt want to cut them off so I opened them up and rotated off on one side. Then I realised that there is a better way for the left side. There is a wire (in the picture) running through the fabric attached to the seat leather, with hooks at either end to prevent it from sliding out. You can fish out the top hook and straighten it, then just pull it out through all the rings and the backrest leather will come off. The foam comes off easily too but it is glued to the top of the backrest frame. Easy to remove but go gently, using a blunt knife, to minimise chance of tearing chunks of foam.
I think the motor at the top in the seat frame picture is the pump for the lumbar support. Hopefully A8 parts will come along and provide better advice for accessing/repairing it.
