Replacing 4-Lug Knott Hub 48" Tank Recon

I am trying to remove the left 4-Lug Knott Hub off my 48" Tank Recon 53AH8ST3050 but don't know how to take it off. I have removed the Cotter Pin, the Shaft Nut and the 6" Stamped Drum but can't get the lug knott hub off. The studs have broken lose and need replaced. Any help would be appreciated.

Penetrating lube and a 3 or 4 jaw 8-ton puller.