Scwhinnbikebob brings up a very valid point about the ring on this freewheel. The ring seems to be made of exceptionally soft metal and unless you have this tool locked down with zero play...tighter than a drum, the tendency for the two slots on the ring to deform horribly is quite high.
If it's the original Atom DON'T use the Park Tool. You will peel the lugs off of the freewheel in a heartbeat. The only way that I have found is to use a big #8 extractor. See pic. I had the end milled off to make it easier to get out of the freewheel. Chuck the extractor in a vice and drop the freewheel on it and turn the wheel. Spray the freewheel with penetrating fluid (I use Kroil) for as long as you can before trying.