I have a fra054xt7 frigidaire ac and would like to clean it somehow, as I feel stuffy and get headaches when I run it.

I have done this many times over the years and it won't hurt the unit. They are made to be in the elements. Unplug it and pull it out of its sleeve. Put it in the yard or driveway and spray it down with a good detergent. Rinse and clean the whole thing. Let it dry out for several days, oil the motor if its not sealed. Be sure it is completely dry and reinstall it.

First you will have to remove it from the window. Next, The coils that you want to clean are not on the face, but in the back of the ac. First remove the face, there should be a way to remove the panel in the center to show a couple of screws, remove those and you should be able to pop the face panel off. next, you have to remove the metal cover, the screws to remove it should be obvious, on the sides and maybe a few on the back. Next, You have to take out the screws which hold in those rear fins. You wont be able to completely remove the fins, as they ar attached to the cooling system, but you should be able to see the dirt and stuff on the INSIDE of the fins. You just have to swivel them out enough to get in there. You can just use a high pressure hose, but in my experience of cleaning hundreds of these things, it doesnt work very well. Youll want to get some acid spray to spray on the coils, and then rinse it thoroughly with water. Its pretty inexpensive...
http://www.amazon.com/Jones-Stephens-Cleaner-S95-721-Appliance/dp/B001C06ERA

and here is a link to some additional help..
http://www.ehow.com/how_7015678_do-indoor-air-conditioner-coils_.html