You have 2 options, either swap the passenger lock into the driver side or swap all the lock pins over to one from a scrappy:
Take the door handle off, and remove the screw from the end of the lock barrel. The locking finger will come off and you should be able to pull the lock barrel out, it can help to put the key into the lock when you do it. At this stage you can just swap your passenger one into the driver side & screw it all back together, job done.
If you want to swap the pins over so both locks work:
Lay the lock down on a clean flat surface preferably in a well lit area so you can see what you're doing. Carefully remove each lock fingers one by one, along with the 2 tiny springs. Make sure you lay them out carefully in the right order on your clean flat surface so you can put em back in the replacement cylinder exactly the way they came out

Next get the replacement cylinder, give it a good clean out then insert the springs & lock fingers cleaning em as you go. Don't use any grease as the locks will work better without. If all goes well you should be able to put your key in, the pins will retract and you can then reinsert the lock into your door handle.
If you decide to just swap the passenger lock onto the drivers side, you could then fit central locking & delock the passenger handle for a clean look, to achieve this simply get a rear door handle, and swap the triger finger over. The finger is held in place with a roll pin, just knock this out swap the fingers over and reinstall the roll pin.
