Habitation Door lock removal on Rapido 740F

[HelenMax]

I've got a Rapido 740F and the internal spring on the habitation door lock has come off, so it won't lock or operate correctly (I know that this is the problem, as I also have a Rapido 741F with exactly the same lock mechanism and can see inside it).

 

Does anyone know how to get the door lock out? It seems to be attached very securely to several things and is not easy to remove. Do I have to remove the outer cover of the door to access it?

 

Any helpful hints/advice would be much appreciated.

Thanks

Helen