Doesn't seem difficult to me. Last time I saw the anatomy of the lock; I noticed a square hole in the center of the locking mechanism. When that was turned, it became unlocked. As the hole is reachable from both sides, it should be a question of drilling a well-centered hole in the door (perhaps start with a pilot hole drilled from the inside). The door handle comes with a bar with a square transsection (just like most door handles) which then is introduced into the square hole of the mechanism from the outside. You fix the handle to the door with a couple of screws, and that's it. I must admit I have not done this, but I have checked out both the lock and the handle - as I considered fitting handles, but abandoned the idea as not really needed.You can start with taking off the lock covers and see if I am right. At least on my car it seemed quite obvious.
Thanks Robbie. I assumed it would be everything you have said. Just need to be brave enough to get the drill out 😂
