This might help a bit
Diag 1 shows the bracket you need to remove No. 8 on the pic
The round bit on the support is fixed to the chamber in the middle with 2 bolts No. 10 in pic
the bottom is fixed to the plate on the back of the engine one bolt above the other.
There are 2 more bolts on the camber one at each end that bolt to the inlet manifold(they go in pointing slightly up at an angle) if you feel round the back with your hand you can feel the bolt head on the right as you are facing the engine.
If you feel a stud and nut that is the inlet manifold not the plenum bolt .They are just below the bottom inlet manifold bolt.
once you have found the first one the other is in the same place at the opposite end your best bet is to reach through under the chamber as the P.A.S. reservoir stops you getting to it from the other end.( I found this easier than trying to get the Reservoir out as you cant get at the lower allen bolt.
The bolts I mentioned at the start you need to get at from under the car .
Once you have removed all the bolts I found it easier to undo the 2 nuts on the brake fluid reservoir and move it out the way as best you can mind the pipes!
Then undo the retaining bands on the air pipes between the plenum and the inlet manifold.
Push the chamber back then once it is free Ifound tipping the left side of the camber down Approx 45Degrees and pull out to the right.
Make sure you have unpluged all the connectors as they all pass over the chamber.
Also there is a connector under the main intake pipe on the throttle body .
I do have a couple of pics of the wires if you get stuck OK.