unlock and lower the handle by the key using the yellow button.... NOW tease the lower release mechanism slightly (above the tail light) - as you do this - you will feel it allows easy unrestricted movement (without breaking) of the red lever, fold red lever out 90 degrees NOW the bottom locking release mechanism can be moved through its full travel and allows the box to come off the bike... almost zero force is needed at any step
pretty sure the instructions state to do this way - its a designed safety mechanism - to stop the red lever folding out accidently
there was a minor redesign at some point... I think the idea is it folds OUTWARD so you can't close the top box lid without fully engaging the lower lock to the bike mechanism
These must never be removed. They’re are compulsory permanent fittings and must contain nothing more than can be carried in a pocket, e.g. old petrol receipts, loose Polo mints, a single grubby ear-plug and a biro that’s run out of ink.