Fan replacement isn't exactly complicated. Power off the supply and unplug it, wait a day or so and it will be discharged enough to handle. If you are in a hurry you can discharge large capacitors with any stout piece of metal (but that may involve dismantling it while the capacitors are still live, not recommended)
If the fan is soldered directly to the board just cut the wires as close to the bad fan as possible. Use the remaining wire to solder the new fan on, or install connectors.