405 glovebox clicking - how to reach air flap servo gearbox?

It started today, and it stops when you push in the "air recirculation"
button. Happens with engine off and ignition on. I gather from the net
the problem is the air control flap gearbox has stripped. But how do you
get to it?

From under the bonnet and immediately under the windscreen I can get to
the intake and remove the pollen filter (very dirty) and see down the
intake past the flap to the (constantly?) turning fan. But how do I get
to the stripped gear?

There are nuts either side of the intake, but do these drop the whole
fan unit inside? Car is a 95 turbo diesel with aircon ... which works
but puts a drag on the engine.

Thanks for all assistance.

Theres some advice on this thread:

http://groups.google.com/group/alt.autos.peugeot/browse_thread/thread/...f1d68cc

but basically to get to the offending gears you need to get in the
passanger footwell and take out the glove box, and then the fan
motor. A fiddly job as u have to work upside down and in the
footwell but not impossible just long winded.