i must be an idiot - help please!

First thing.... You are an idiot! You need to ditch the carbon fiber shift knob

You need to pull the radio out of the DIN sleeve first. The black plastic trim piece has a bracket that screws into the back, near the firewall. But you can't get to the screw until you remove the radio. Once you remove the radio, you can remove this screw which will allow the plastic trim piece to be removed (not necessary, but it's a pain if you need to remove the

You know what the DIN sleeve is, right? Well, if not, I will tell you anyway. The DIN sleeve is the metal sleeve that the radio slides into. You need to slide the radio out of the DIN sleeve first. See the two aluminum-looking metal tabs on the left/right of the radio. Those are tabs that are a part of the DIN sleeve.

What you need is something 3" long, and very thin. I have DIN removal tools that came with my radio, but most radio's don't include them You can substitute this with a very thin alan wrench. It worked for me. Take the long portion of the alan wrench, and slide it inbetween the radio and the DIN sleeve, inbetween the two aluminium-looking tabs. That is where the locking tab is; and the alan wrench will push it out, allowing you to slide that side of the radio out. Once you get the alan wrench in, stick your other hand underneath the radio (where that light blue box is), find the back of the radio, and pull that side towards you. That side should slide out only about 1/2" or so. The other tab is holding the other side in still, so you need to release it.

Once one side is out, do the same with the other side. Once the alan wrench is in the other side, pull that side from underneath. The whole radio should slide out now.

You may need to wiggle/play with it to come out. Sometimes there are tabs above/below the radio, but they usually don't prevent removal, just make it more of a PITA.

Once the radio is out & wires are disconnected, look inside the gap where the radio used to be. There is a screw way in the back, that attaches the plastic trim to the back of the entire console. It's a torx screw. You don't need to remove this, but since you will have the radio out, you might as well take this screw out in case you need to remove the trim piece.
Scott