I just picked up a Schwinn Woodlands with Biopace SG cranks on it. I'm cannibalizing it for parts. When I went to remove the cranks, I discovered that they were bolts instead of nuts, and I couldn't get my Park crank removal tool to work. I didn't force it, though. The threads fit. Does this require a special tool, or do I just need to give it some WD40 or other stuff and push harder?