As it says chaps - any clues please? I have freed up and sanded all the other flaps and they now move freely but I'm buggered if I can see how to remove the top flaps without damaging anything.
Once done I'm swapping the boxes over so my blend motors work automatically again

Need to pull the driveshaft that runs through them, and then pry one edge of the flap so it pops out.

They're pretty sturdy and I haven't managed to break one yet.