68 Alternator fan and pulley
 

What is the easiest way to get the alternator fan and pulley off? Is the retaining nut reverse threaded? Do I need to take the alternator off the car completely to do it?

take it off, put a screwdriver between the fan blades into the front of the case side, impact wrench the nut off. it's standard thread so counterclockwise for OFF.

Don't stick a screw driver in the front of the case. This is
not necessary and you will scratch it up! Just put an impact wrench
on the nut (The type of impact used on lug nuts) and hit the button on the gun.....the nut will come off in 2 seconds without backing up the fan blade,,,just let the blade free wheel while removing. The same
goes for reinstalling the nut...if you back up the fan blade or try to
hold it when tightening the nut with an impact you will overtighten
the nut and ruin the alternator front bearing.

alright, let me clarify that the screwdriver only goes in far enough to rest on the edge of the opening to stop brace the fan from spinning, not driving it deep into the heart ending it's life. without doing that, I'd keep my fingers FAR from that fan because if that shaft's stripped or rusted, and your hand's anywhere near it you'll be looking for your fingers.