I noticed no one had replied - I have a 2002 but if they're the same it's about easy as can be. Mine just has bulbs plugged into a plastic housing that you can get to by removing the rear access panel(s) inside the car.. It may be a totally different set up for a 2005 but it still should be pretty easy.
It's the front turn signal bulbs that give me grief. Doable, just a pain in the arse.