You should not have to "remove" anything. Either loosen the alternator, or if installed, use the tensioner to loosin the belt, and put the new one on.
It's a bit easier using the alternator (if easily accessible) cause the tensioner you have to hold up (or down) while pulling the belt off - and gettin' it back on is a bit more difficult this way.
Let me know if you need futher assistance.
carsandcomps,
Guru, Premium Expert @ Fixya.com