be careful because even with a propane torch you can melt the impeller Aluminum) unless it is stainless or steel composite.

The little plastic liner for the impeller/shaft likely will need to be replaced due to the corrosion that is holding it on the shaft. Keys are also cheap.

Use anti-seize when putting back on.

Also a little heat on the pin channel should help at both ends of the foot. Or heat it warmer than you can place your hand on and let cool or cool with a garden hose as sometimes this will break the corrosion.

Use no bigger than a 4 lb hammer and a good long pin punch