Treborsweet

HI all i have a V Class EQV and yesterday the tailgate no longer opens from the outside tailgate release button/catch? it works from the remote tailgate release?
its almost like the button that tells the tailgate to open is not working.
These are the same as the normal V Class i would imagine, has anyone has to change one before or is there something like cleaning the switch?
How hard are they to change if needed?

Thanks.