There are a couple (at least) ways to go at this job.

1. put a pry par beside the alternator, inside the belt and pry against the base of the alternator where the front bolt (drivers side) goes into the intake. While holding tension on the belt reach under the tensioner and flip the "kickstand" up and hold it while releasing tension on the belt. I'll post a picture for you if I can figure out how to post someone else's.

2. grab the belt with both hands while standing by the passengerside fender. pull real hard to get some slack, it will take both hands to move it but once you have some slack you can hold it with one hand and flip the kickstand up with the other.

3. pull back the rubber piece where the small shroud piece connects to the main part of the shroud (looks like a strip of small tubing) you will see there are several locking tabs where the two pieces meet. using a small screwdriver, work your way around the tabs and remove the small "eyebrow" panel from the main shroud, be careful, it breaks easy. this will give you room to put a tool in the 1/2 drive slot on the tensioner.

4. just unbolt the alternator, it's a bit of a pain to put back on but it can be leveraged back in place.

personally, I used to do #3, but #1 works a little better. My discription isn't great, but I'll try to come back and post a picture for you. theres a good one floating around here somewhere.