Old thread but I just did this so...
Noticed my license plate lights were out so I checked both fuse boxes and found no blown fuses. I found it odd that both bulbs were out at the same time, but come to find out they were. Here is how I replaced them.
1. Put your top down, the top in the trunk will expose the whole inner trunk liner.
2. I used a small straight blade screw driver to release the plastic pop fittings around the gray liner. There are some on the vertical part as well so give it a good look to remove them all.
3. Release the small "center brake light" sockets on either side of the now exposed steel plate by hand. This will allow the liner to come down.
4. I pulled down on the liner to get under and behind the liner to release the trunk switch housing using the same screw driver. Be patient so you do not brake the clips. Use the same technique to release the alignment housings on only one side (removing both is not required)
5. Roll down the liner until the license plate light bulb sockets are exposed, turn them counter clock wise and they come away, then just pull out the old and put in the new.
6. Assembly in reverse order, everything just pops back in no fuss. Easy now that I have done it once and know how the clips come away. Resist the urge to just pry out the switch. If you are patient and reach the small clips behind it will come out easily. Hope this helps somebody.
Cheers