If you have a look at the aircon pump and the alternator (both are belt driven cylindrical items) you will notice that they are fixed with bolts, loosen the bolts...don't remove the bolts...then the belts will be slack enough to remove (13mm socket and ring spanner is usually a good combo).
Refitting is a reversal of the slackening proceedure...do not over tension the belts...this can be checked by twist the belt with your fingers from the horizontal postion to the vertical, if you can't....it's too tight....i'm sure you will be able to tell if it's to slack...but the ultimate check would be (after you have checked that there are no tools ect left in the engine bay) start the engine and turn on the rear heated window and put your lights on high beam, if there is a screaching noise...then your fan belt is too slack...hope this helps.
Stevie B, May 2009