Hi ive got a ford transit lwb r reg and the drivers door has jammed and wont open from the inside or outside we have taken the door card off from the inside and the barrel is working fine the door handles and linkages are ok it seems to be the latch has either seized or is broke we have drilled the rivets and removed the metal plate behind the barrel to get axcess to the latch but the latch has a case around it and we cannot remove it because the screws for the latch are obviously on the side of the door which we cannot get access to without opening the door any ideas how to remove the latch and get the door open ?