So, after delaying the job, I thought I’d try another method.

I zip tied the lock so it was out of the way, and to avoid hurting my fingers, I just used a long nose plier to get the short end behind the little plastic part.

The only issue I have is I’m finding that the pin hole is not aligning at all. I can, however, manually align this myself if I adjust the plastic hook. I wonder if this is normal or that I’ve done something wrong.

If you push the cam a little bit into place, together with moving the handle and wiggling the entire contraption, it will go into place! Do not lose heart!
PS: do not forget some harsh language, always helpful!

My door handle pulled out of the door today. The metal post that holds the roll pin has snapped which makes the handle unrepairable (as far as I can tell).

Does anyone here have a spare RHD drivers door handle available? I'm waiting for a few breakers to get back to me but most don't seem keen to sell just the drivers handle.