just changed mine for the first time last week....
miatman, i just did this last week so its fresh in my mind.
I hope this helps and makes sence. it's easier than my explanation makes it sound.
you need a 15mm socket, and a breaker bar or like mentioned above a length of pipe to go over your ratchet. you may also need an extension on your socket. With the tools i had i needed one because the clearance between the tensioner bolt and the fan blades was not wide enough. so i had to actually rotate the fan blades around to find a spacing between the blades that was large enough. ( the fins on the blade are not all equally spaced some blades are farther apart then others) if you don't see it right away the fan shroud has two quick release latches that hold it on. one on each side.
Just to clarify though the bolt you were talking about taking off is not the one you want to use. That bolt removes the whole pulley tensioner assembley. the one you want to use is to the right. The bolt that is in the center of the actual pulley.
place your 15mm socket on it and crank it clockwise until you have enough slack to slip it off the alternator then you can release the tensioner pulley and remove the whole serp belt.
you will find it hard to get the belt off of the large main drive pulley on the lower front of the engine because the clearances between that pulley and the fan pulley is really tight. I could not remove it while i was looking down on it from the engine bay. I had to climb under the front and twist the belt up so it was 90degrees to the pulley, so that i could wiggle it up and out between the two pulleys.
also definately make sure you make a drawing of the proper belt routing BEFORE you take the belt off. (i kept my drawing in the glove box so if for some reason it breaks i won't have to guess or worse rely on my memory.)
this is also just my 2cents but, if your old serp belt isn't completely shredded or sliced in half you can keep it in the back of your disco along with that 15mm socket and breaker bar, so if it breaks when you are on the road you can replace it with the old one and get home, and buy a new one.
