Changing back- and front lights on a Passat ?

salut there,
I just bougth some new back- and frontlights for my WV Passat Limo (3B2 96-00).

I have looked in the instruction manual but couldnt find any directives on exactly what to do, to get the actual housing out. Can anyone guide me on how the get the housings out, to get the new ones in, ou is this something i should not do myself ?