1994 XJ6 Alternator

I have a 1994 Jaguar XJ6 and the alternator went bad. No problem, because I found one in a junkyard for $60. My problem lies in the fact that I don't know how to take the old alternator off! I've found the two bolts that hold it on, but I cannot find a tensioner to undo so that I can take the belt off and on. I don't think there is a tensioner, and I think that the bottom bolt is the one on which the alternator should pivot to take the belt off and put it back on. I simply do not know how to do this swap, and I need to find out quickly because I am trying to sell this car within the month before I go back to college (college students should never, on a whim, buy a Jaguar!) Any help is greatfully appreciated whether you know how to do the swap or if you'd like more information on the car! Thanks!