Hi all newbie here, After a bit of advice for N plate galaxy of grandads. Over icy period lock froze, jammed, he got key stuck so kept wiggling ad eventually got key out. now lock on outside just spins with no reistance, inside handle wont open door. I have unplugged motor and plugged it back in pinging the locking but not undoing it. He has had lock replaced before as seems a common problem so thinks he needs a new one which is fine i can fit it.....but how can i open the door to fit it without destroying the car? All help appreciated thanks james