It is not hard, just time consuming. The most annoying part is getting the fan shroud and fan out if the way. Everything else is not too bad. I replaced my power steering pump seals a few weeks ago and took care of the belts while I was in there. All told it took me a couple of hours due to some complications with the ps pump.
Three quick pieces of advice:
First, pay attention to the orientation of the pulley immediatly behind the fan (the one the ps belt loops around). It can go on either way and getting it wrong will leave you throwing the ps belt due to misalignment.
Second, remember that with the ac, ps, and alt belt all pulling in different directions on a central point, adjusting one makes you have to adjust the tension on the others.
Third, remember to recheck your tensions after a few miles as the belts will stretch a bit.
Good luck.