I have been able to remove those OCC cranks without the tool. Those cranks are steel . . . might have something to do with me being able to remove them. You need to remove the chain guard first. Then loosten the bolts about two full turns. Lay the bike on its side. Grab the crank near where the pedal attaches, and while sitting on the frame, pull and push the crank up and down. It fits on a tapered shaft, so you just need to work at it. The first several times, you might not see or feel any movement, but unless the cranks are rusted on, you should be able to get them off. Prying on them will NOT do the job. Remember that the sprocket is afixed to the right crank and it will stay on the crank. Once you feel the crank move, remove the bolt and you got it! I have removed the cranks from 4 different OCC choppers this way.
Aluminum cranks are a different story . . . you'll need the tool!