I had the same problem with rear drivers side door on my Skoda Superb. The dead lock went on but wouldn't come off, either with the remote or the key. My mechanic managed to remove the inner panel and chisel off the old lock. Fitted a replacement but didn't connect the wiring. Now the door locks on the button on the door manually and unlocks when you pull the inside door handle, once to unlock and one more to open the door.
HTH Graham
i looked into buying new locks but after chatting to a mechanic mate, it seemed it might be cheaper to buy whole new doors -as its easier to fit a door, than opening them up, mess about removing old lock installing the locks etc
the doors were not much more than the locks