I replaced the passenger side last year...there are 4 or 5 bolts along the upper part of the fender, a couple of bolts on the front core support, 4 or bolts in the fender wells and you will need to remove the bumper filler and unbolt the hood hinges. THe really tough part is getting the fender back on around the fender wells I had trouble getting everything lined up, but with two people it's a much easier job.
Didn't need to remove the header, actually there are pins in the Header panel that help lineup the fender. It's pretty straight forward just make sure you keep track of the exact spots the bolts came from they are not all the same size but look alike. I had the fender installed on the first try then realized I switch a couple of bolt and ended up have to remove the fender twice.
