Remove crank, do the heating thing if you feel like it, attach pedal spanner so that you can stand up the spanner/crank like a shallow triangle, put on hard surface you don't want damaged, stamp on tip of triangle (making sure it's undoing clockwise).
Remove crank, do the heating thing if you feel like it, attach pedal spanner so that you can stand up the spanner/crank like a shallow triangle, put on hard surface you don't want damaged, stamp on tip of triangle (making sure it's undoing clockwise).
Someone posted a picture of this method before...