One other thing you can try is to use the impact method, which is to strike the end of the cog tool with a small sledge hammer. This will multiply the force many times w/o damaging the wheel. This is a job for two people.
__________________
What, Me Worry? - Alfred E. Neuman
I'd like to think i have as much money as brains.
I see the light at the end of the tunnel, but the tunnel keeps getting longer - me