On the Acadia you have to remove the inner wheel well, and once you do you must rotate the bulb accessory cover counter clockwise to remove the bulb. we charge $87.10 + tax at our shop to change these unless you have hid lamps then it runs about $365 + tax.
You can buy a set of new bulbs at Walmart for under $15. I have changed the bulbs on my Acadia 3 times now. It is not hard to change them. First turn the wheel so it opens the wheel well cover so you can just unscrew the front portion of the cover. It is not neccessary to take the whole thing off. You will then reach into the light cover and unscrew the access cover. When this is removed you will then screw off the bulb connector and that will allow you to disconnect the bulb from the wire connector. Reverse the steps and put everything back together. This should take you 5 minutes. Maybe it will take you 10 minutes on the first one you change out? I always change both driver and passenger lights when I have a light out. Maybe I am crazy, however this allows me not to have to worry that the other one goes out a few days or weeks later. If anyone tries to charge you more than maybe $30 to replace those lights they are crazy or ripping you off.