Connections changed in 2007 so make sure you get the correct one. The pulleys are the only difference between the standard GS and ADV models and can be changed over, or fit corresponding alternator belt, 595 standard GS, 582 ADV .
I usually end up getting them for customers off USA ebay, almost always like new and a quarter of the UK breakers price and generally arrive within 3 days.
Basically remove front alternator cover and upper plastic surround, remove tank and undo alternator securing bolts, lift out through the front - replacement is opposite of removal. .