You don't have to... access back there sucks though. You have to take the access panel off in the hatch. The upper bulb is the brake light, the bulb twists out with a 1/4 turn. Pop the old one out and the new one in. That's pretty much it. Again, it helps to have small hands. And don't drop the bulb, it'll fall into the fenderwell, and it's a pita to get it back out.
Hope I've scared you enough.