I'm hoping this is close enough to a Shower & Tub question -

I used a diamond cup wheel for the first time to remove adhesive residue on a concrete bathroom floor. It is a 4 1/2" double row spin-on DeWalt DW4774, so it doesn't use the backing flange, lock nut and wrench all my other wheels use. It worked like a charm but now I can't get the darn thing off!

Is there a trick or a special tool for this? It seems like it's going to take a lot of leverage but I don't know whether to grab it by the holes or the segments or what. I hate to damage or unbalance it, they ain't cheap!

Thanks for any help.