I have used TANGO'S method befor,IF the WD40 dosn't work try squirting some transmission fluid in the cylinders and let that soak for A few days befor trying to turn engine over.when your buddy get's it freed up and running Id have him do A compression check on each cylinder just to make sure no rings were damaged in the process.(GOING TO SMOKE LIKE A FREIGHT TRAIN )for awile.