lol, we all have those moments in life, if its a newer model car its best to take it to a body shop as theres quite alot involved, fender is usually 3-5 hundred, labor around 250-3, if so inclined and want to go the cheap route, part can be found off e-bay, or local junk yard, best to purchase already off the vechicle, that way you can see where all the bolt holes are. a helpful tip is to go and join a automotive forum, say for example you have a "doow" toyota camry use that for your search ie: toyota camry forums, you would do your your search under body restoration or repair. if fender r&r isnt listed any where you can ask how to in that section of the forum.
That pretty much sums it up. What is involved? How much does it cost? Can it be done do it yourself?
Later It kind of works this way. If you want it to match the previous fender design, it probably will cost a few hundred plus paint. If you don't care what kind of car it came off of, it's a LOT cheaper. ;D