Rear Door won't open

My rear door (drivers side) won't open - from inside or out.

I have managed to remove the door card - not easy, but possible if you remove the base of the rear seat and the trim over the rear wheel arch.

I am now faced with another metal plate inside the door - retained by bolts.

- If I remove this, will I then be able to open the door by manually accessing the catch ?

- When removing inner door plate, should the window be "up" or "down"

I suspect the problem is either mechanical - ie need to replace door catch, or electrical due to cracked solder joints in the door handle module.

any help appreciated :1zhelp: