Discovery 300tdi door locks.

Hi guys and girls, I know this is an old chestnut but it is driving me nuts. I have a 1997 disco 300tdi. The passenger side front and rear doors do not open. It is as if the button just doesn't rise high enough. If I pull the button up manually just a mm or two the handles work fine. I had the door cards off to adjust the threaded link rod that connects to the exterior handles a couple of turns to give them extra pull but I could not find any adjustment for the mechanism itself. I also lubricated the actuator mechanism to see if that was the problem. There are a lot of threads on here about replacing springs, is this a route I should go down? When I tried to remove the top window frame to get the lock mechanism out I also rounded off the torque bolt on the outside of the door at the top on the front door just to make it more interesting. Any advice on how to remove that would be great for starters, lol. Or can the lock be removed without removing the frame? Also, would it be adviseable to cut out a small access panel on the inside of the door beside the lock to get easier access to the mechanism itself?

I need to fix the boot door mechanism also but I might leave that for another day. It doesn't lock with the central locking. The button just springs back up again.

Any help or advice would be most appreciated.

Thanks, John.

i had this prob with rear doors n tailgate got spring kit from ebay plus spare door card clips all working great now, look at post by sticky titled disco door springs, wish he did this before i had probs looks great step by step help, goodluck