Power tools help, but they aren't totally necessary. If you have a friend with an impact wrench, that's all you'll need...as far as the tensioner, loosen one bolt and ur golden because it's spring loaded, so you just need a screwdriver to pry it to the loosen position and the belt will literally fall off.
The hardest part is getting the belt on, and only because the routing diagram for the belt looks nothing like the side of the engine. If you get the FC 2 pc kit, you use the stock belt, so that makes it easier in that aspect, but harder because of the location of the water pump pulley (brace in the way of taking it off, so you have to use a wrench to wiggle up in there and loosen the bolts, but not overly difficult to do).
There are a few how-to's out there as well with great helpful hints to getting the crank pulley swapped out. I think I read somewhere on one that they used the tire iron as a wedge in between the lugs to keep the crank from turning, then you can use a wrench with some sort of cheater bar on it to get the crank bolt loose.