I assume you mean the rear license plate. Pull off the rear door inner panel -this comes with a firm pull, it is retained with spring clips- and access the bulb holder this way. You need to depress the two legs either side of the holder before it will come out.
you need to remove the inside panel to get to these bulbs
Check bulbs
The clear covers for the license plate light bulbs have small arrows pointing in one direction. Simply push the cover to the direction of the arrows and the covers will slide off allowing for the old light bulbs to be replaced.
I had the same problem with my 2000 Passat. According to my mechanic (an excellent independent), the vent cover over the bulbs is not removable without breaking it out. So you may need to buy a new bulb and a new vent cover ($100+).
They are located inside the trunk lid, underneath the felt lining. You need to unsnap and pull back the felt lining to access the bulbs for the license plate light.
in the rear facia, under the trunk lid there is 9 bolts holding the facia on. You must remove the nuts and pull the facia out and right above the license is the two bulbs 194. replace the bulbs and put the facia back on and you are on your way.
If you can not remove fasteners on outside, you may need to cut a section out of the inside of trunk to get your hand by the bulbs.
NO
Have you tried changing the bulbs first?
push up and turn on the housing
If you are afraid of breaking something take it to a garage.
You need to remove the liner on the trunk lid. That will give you access to the license plate lights housing. Remove the sockets by twisting 1/4 turn and replace bulbs. Size for bulbs are 2825