Does anyone know how to replace the driver's door lock since its been going bad for some time.

If the key is turned to the right, it unlocks the doors and sometimes opens all the windows (bar the back passenger side which has broken) and turning the key to the left has no affect at all. You can turn the key almost 360 degrees and the lock doesn't respond at all.

If the passenger's door is used or the boot, the locks will open and close fine.

Its just frustrating when you want to get in and just drive.

The lock is held in with a cage which rotates to align cut outs with ridges in the lock barrel. Open the door and remove the small plastic plug, using a torx unscrew the screw, it has a large head which rotates the cage. As you unscrew it use the key in the lock to gently pull it. Take care not to undo the screw too far or the cage will drop into the bottom of the door.

Some cars have additional conventional torx screw under another plastic plug which must be completely removed.

Skoda do repair kits for locks, though there are some locks used that are not designed to be taken apart

Someone had a similar problem with a Fabia, so this might help:

http://briskoda.net/fabia-i/fabia-lock-failure-replacement-options/139508/?highlight=door+locks

There is a guide int he technical section

i have a rear passenger central locking module for sale if you need it?