Side Door Catch for Outside Table

[ceegee]

I am considering replacing the catch which holds the outside table in the side door - it sticks and despite some of the "fixes" I have read about, its not sorting it.

Has anyone done this job i.e. removed the door trim and replaced the catch - if so, does anyone have advice??

My local dealer wants £108 to do the job - feel sure it can't be that difficult - can it??