I've got a 197 and it should be the same on the 200's.
Open up the boot lid and on the black plastic tht dips into the groove of the boot lid where it shuts, you should see 3 black screws. Undo them and carefully prise the light unit away from the car. You will find 2 white poppers on the left side of the light also.
Once the light has gone off, you unclip the black plastic from the casing and you now have access to all the bulbs.
You do the reverse to put it back obviously.
Hope this helps Tom.