The Aux Fan replacement is an easy job, but it would've been nice of the shop to tell you that it didn't work before they charged the A/C. Plus, without a working aux fan, I'd be impressed if the vent temp hit 65 degrees. Maybe when under way and with high RPMs Either way, having to work around a charged system isn't that big of a deal, but merits some extra caution.
Front bumper removal is covered on Fong's web site: http://home.comcast.net/%7Efongman1/. Only tools you should need are a long flat blade screwdriver, trim remover (can also be done with the screwdriver), 17mm socket. It's easier to take off and reinstall with two pairs of hands when doing it the first time around. Also, before replacing the fan, verify what the shop said to be true -- see if you can manually rotate the blades. The aux fan resistor is a common shortfall, and without a working one, the shop could conclude that the fan is "siezed", when in fact it is just a low speed issue. But the magnets also dislodge themselves, so the fan could be siezed.
best, whit