When removing one of these, especially if the part had been damaged, I used to hold the tool in place with an axle nut. Don't tighten it down on the tool, just screw it down far enough that it won't let the tool slip off. If the part was damaged I might even put the axle nut on finger tight so there was very little play in the tool, but you need a little play to make it work. Even VERY little play will work if the part is damaged, but tightening the axle nut makes the freewheel an unmoveable object.
With the tool and nut in place, clamp the tool in a vise and twist the wheel counter clockwise to break the freewheel lose. I don't think I've ever tried to hold the wheel and spin the tool with a wrench, holding the tool in the vice is standard procedure no matter what freewheel tool I was using.
Once the freewheel breaks loose from the hub, you have to loosen the nut to allow the freewheel to spin off. If you don't do that, all you're doing is tightening the freewheel onto the axle nut and your progress will quickly stop. You have to loosen the axle nut as soon as the freewheel breaks loose from the hub. Did I mention the axle nut is only on there to hold the tool in place while you crank on the wheel to break the freewheel loose from the hub? Once the freewheel has broken loose, you have to loosen/remove the axle nut. You will probably have to remove everything from the vise to do this, but you can probably screw it off by hand now anyway.
In my years as a mechanic this method removed a lot of freewheels that had been messed up by people trying to pound them off with screwdrivers or punches or nail sets or whatever else some kid could find in dad's toolbox. Or so Dad would claim when he brought it in...
PS - clean up the parts first. At the very least you should clean the interface between the tool and freewheel.