When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Its pretty easy. Just use a ratchet or breaker bar to rotate the belt tensioner arm. There is usually a square hole in the tensioner arm for a 1/2" breaker bar or ratchet. Then pull the old belt off. There should be a picture of the routing of the belt next to the emissions sticker under your hood by the fan shroud. If not remember how it came off or draw a picture. Then put the new belt on the same way the old one came off.
I changed out my belt on my '97 4.6 at 150,000 miles - way too many miles, but the belt looked so good I kept it as a backup - I'd highly recommend Motorcraft as a replacement. As for the task, it wan't bad. Study the diagram under the hood carefully - maybe sketch it on an index card to use underneath - keeps you from doing the "up and down" when putting the new belt in. I did 2 things to help out - used a 1/2" flex handle with PVC cheater to position the idler pulley. Also made an "L" out of some 1/8" rod to help position the new belt around one pulley - it's a bit tight in a couple of places. Nothing has to be removed to change out the belt.