I just bought an older bike, Diamondback Outlook, the entire rear end was caked in dried mud, the freewheel is almost completly seized, probably due to mud.
I got the freewheel off the wheel, but now I am having problems knowing what to do from here. I am pretty sure that it is a Hyperglide freewheel, but elsewhere I people are saying that the FR-5 is the tool to remove a Hyperglide freewheel from the cogs. There is nowhere on my assembly that a FR-5 will fit. I used a FR-1 to remove the the freewheel from the wheel.
This is what my freewheel looks like (picture from Harris Cyclery)

I have tried to use a nail and hammer to turn the ring with two holes in it counterclockwise, but the darn thing wont budge AT ALL. I assume that to clean out the muck and dirt that I will need to get into there. I have tried flushing it out with solvent (brake cleaner) but the solvent is coming out clean, but the freewheel has a real gritty feeling to it still.
Any help is greatly appreciated.