Help with broken aircon controls

[Toya1]

Hi all, I got a used Avensis (2009) a year ago and whenever I've had any problems, this forum tends to be a great source of solutions. So I was hoping you could help me with a strange issue.

The control for the aircon doors has broken so I can't change between the settings. That's obviously a major issue as it's hard to de-mist the car in the morning.

There are 2 issues with it. Firstly, there's a cog that effectively controls 2 different levers inside for the different settings (pictured). That's fallen out. It happened once before, and I managed to get it back in. It's really hard to do because it's up under the middle in the drivers footwell and is really hard to get to. With enough perseverance I could fix that, but not this time, because of the next issue...

The second problem is that this time it's more apparent as to why it's popping out in the first place. One of the levers that goes into those groves has broken — it's totally snapped, but quite hard to gauge what's going on because of where it's located. So I'm guessing something was misaligned in there previously. Whatever the case, I now need to figure out how to access it to fix it.

I'm a bit of a car amateur, but I'll give most things a go. If something breaks in here—how does one normally go about accessing it to fix it? Do you take the dash to bits? If you just remove the stereo etc can you get in there, or is that bit of a sealed box?

Alternatively, if someone knows a good place to get this sorted at around the London/Croydon area I'd appreciate any tips.

Thanks in advance everyone!