I is a bit of a PITA, but I don't know about 3-4 hours unless you run into a problem. Definitely replace all the belts if you are going to take the trouble to do this (the alternator/water pump belts are on the inside anyway). I think it took between 1 and 2 hours the first time I did it. The last time, I did it in a hotel parking lot in about 1/2 hour (barely got dirty). The trick is knowing all the tricks, like the best way to reach all the bolts. It also helps if you know nothing was over-tightened the last time. I also found that the OEM belts last longer than the "part store" brand belts, I don't believe the part store belts are actually the correct size.

If it's too much of a pain, just bring it to your indy, the labor should only be about $50.