Heya. Just a quick post in case some of you find this useful.
Changed the broken front left door handle today including the lock swap.

Here's the busted bit above my thumb:


Dont try and push the little lock buttons in and slide the barrel in with a screwdriver like this! It will result in explosive swearing attacks, and possible tool/lock breakage:


Just put the key in to pull the tabs down..


..and hey presto:


Now my girlfriend can let herself in and I can give the gentlemanly game a rest