You need to remove these screws:





Then you can put aside the 2 electrical harnesses (3 + 1 clips) and unplug the 3 connectors from the SDARS tuner:


And finally you can remove the whole bracket:



From what I see, I believe you will have to remove some more carpet before you can remove the bracket.

Hope this helps. Good luck!

 

Thanks, definitely helps! I do then have to remove the trunk carpeting that goes all the way forward to the rear seats.
Just have figure out now how to get it out.

Out of curiosity, where did you get those images from?

 

Wanted to give an update on the progress, or lack thereof, lol, in case anyone may have suggestions.
I'm still having the same problem where my B&O audio system is not turning on.
ICM control module turns on and displays "Bang & Olufsen" for a few seconds, but then turns off and nothing works, no tweeter rising.
The display is on and shows the weather, and I can still scroll through the menus and try to select an audio module, but after I select anything it just goes blank again.
All fuses seem to be operating properly from testing with a voltmeter.

I took the complete interior apart and have tested every individual MOST fiber optic audio module, and even individually tested every fiber optic line with a laser to trace each components before and after connection.
All modules pass through light as they're supposed to.
The only part that still does not turn on and does not pass the MOST light is the DSP amplifier. However, even after I bypass the amplifier with a loop tester nothing changes, the system still does not turn on.

Thanks to the diagrams above by @EJ_Rapide I was able to get the DSP amplifier out and and sent to check for damage. I took it to a local electronics repair shop and they confirmed there were some burnt chips in the amplifier and replaced them. However after reinstalling the amp unfortunately it did not change any of the issues. The main thing is it still seems the DSP amplifier is not turning on/or outputting a MOST signal.
Reading through the fuse diagram there are a couple of separate ones for the amps and then for the amps "MOST Wakeup". It's possible they have something to do with it but I haven't figured out how those controls operate.

One interesting thing I discovered while testing is there are actually 2 MOST light sources. Both the ICM display screen and the IAM (CD/Radio) devices output a MOST light signal on their own.
I initially thought only the display screen was the original MOST source. One test I did was to install 2 loop testers on the ends of the ICM and IAM, so technically only those 2 components were in the system looped to each other. But that didn't do anything, still had the same issues. I thought perhaps this would turn the system on since the MOST loop would certainly be complete, but not the case.

I think I've exhausted every possible issue, and only next step is to take the car to a main dealer to check if it's an issue of reprogramming the ICM module or dsp amp.
If anyone has any other ideas I can try out I'd be happy to hear about it!

 

Problem Solved!
Well, multiple problems solved in the end.
The DSP amplifier had some other damaged internal circuits the electronics shop was able to repair. After it was done the amp finally turned on and was outputting a fiber optic signal.
Once that was up and running then we discovered the Sirius SDARS module was outputting a bad MOST signal, so that was bypassed and finally for the first time the audio system screen turned on!
However..... there was no sound! And still no rising tweeters, lol.
So then back to frustratingly testing everything again, and after several more hours we found the problem was bad grounding.
As it turns out, the audio system components in the trunk do not rely on their own wired grounding, they require the components to be bolted down to the frame and chassis. Otherwise the fuse box does not supply the full voltage from the battery. The components had been randomly receiving only 5v from the fuse box, hence not fully turning them on.
As soon as we attached an additional wire to the chassis, everything magically turned on, tweeters went up, and everything worked!

Also for reference if anyone is testing their systems, there are 3 components that provide their own MOST light source, the IAM, ICM, and DSP amplifier all produce their own fiber optic signal. The other components rely on the incoming MOST light to turn on.

Thanks all for the help in getting this sorted, such a relief!

 

Glad you got it working! What an ordeal. If you want the Sirius to work again, there's nothing really special about it. You can install any volvo unit with the same connectors. What you really want is a unit that has a lifetime subscription though. Aston from 2008, 2009, maybe 2010?

 

I'm not worried about the Sirius module actually, I've never listened to Sat radio so I just left it bypassed.
I got a Bovee iPod Bluetooth adapter so I can just listen through there if needed.
I was thinking of maybe putting in one of the DAB modules in its place. The car actually comes pre-wired for both antennas connectors.