Popping the tail lights off isn't too bad, I've done it countless times.
Follow this DIY until you hit step 7, and then what DEpointfive0 stated, there will be a 8mm nut you have to remove, and then 2 bolts on top, after that you disconnect the cable harness. After all said and done, I did not put that 8mm nut back so I can easily remove it. It's been like that since I've owned the car for almost 4 years with an Amuse kit so I can tell you no harm done if you put that 8mm nut or not.
Here is the DIY I was talking about
:
Removing the Trunk Interior on a 370Z -> Z1 Motorsports
Follow the interior removing steps until you see the pic on step 7!
Good luck bro!
EDIT
I didn't read all the way that you just want the bulbs changed, I never bothered trying it, my bad.