I use a 12" adjustable wrench and a rubber mallet. Engage the remover into the freewheel (as mentioned above, using the QR, if so equipped, can help hold the tool in place); lock the wrench onto the remover, push the wheel against the floor and wall; and give a couple of good whacks of the mallet on the wrench. This method has worked great even on 30 year old stuff dug out of a dumpster.