The shaft on mine had a flat on it that matched the hub to keep it from slipping.
It had a thin retainer with a clawed inside area (it also had a flat to match) to hold the fan assembly in place.
Other that the shaft needing cleaning and some WD40 to reduce the amount of resistance, the hub was just a snug fit.
In my case, I think I pried too much in one direction on the first. I use two screwdrivers opposite to get off the second.
Putting it back on will be much easier
Jerry
