So helpful folks here helped me get the cog and lockring off, and now I'm stuck with this. I looked on Park's website again for "removal of freewheel" help, but mine didn't fit with any of the methods. No hex wrenches, screws, bolts or anything. The ratcheting mechanism just seems sort of...on it.
There's two notches (picture below), screams "two-pronged tool" but I'm starting to think this wheel simply cant be converted to a fixed wheel. New rear wheel perhaps?