Dead easy. Undo plastic nut, undo wiring connector, (pull side clip gently to one side to free it), push lamp unit back from inside car, you may need to push in plastic "barbs" gently so that assembly will move past them. Push it straight back until the locating pins are free. Separate bulb holder from lens unit, again by pushing "barbs" to allow them to slide out. Replace bulb. Reassembly is obvious, make sure all foam and rubber seals are seated correctly to avoid water getting in when it rains, and reconnect the electrics before doing the nut up. Don't get any wires trapped.
Whole job takes 5 minutes when you've done it once. The first time it took me 15 minutes.
Good luck, don't break anything.
ChicksFan
October 2009