very easy to do as just done it on my own Cav.
disconect the battery(very important).
remove the air intake pipe as this will give better access to the alternator.
remove the to electrical wires from the back of the alternator noting which goes where.
then remove the 2 brace bars at the top of the alternator. this will leave the holding bar at the bottom of the alterator.
before you remove this unplug the electrical connector at the side of the alternator as this will make it easyer to move it.
Now comes the hard part. you will need 2 spanners/ratchets to remove the last bolt and this can be hard to do. Once you have removed the bar the alternator should just come loose and can be removed.
refitting is reverse of removal. To put the tention on the belt use a piece of wood to push the alternator back until its tight then tighten the bottom bolt.
Thats it. total time is aprox 30 mins due to the bottom bolt. Oh and remember do not put pressure with the wood on the black plastic part of the alternator as it will break it.
hope it helps
rob
rob, January 2010