17 year old tyre on the rim for 17 years. Bead would not break by the methods suggested. I resorted to a car jack to break the bead. Support wheel so it is level and the jack won' slip out. Place jack under something solid or heavy (like motor vehicle) with the base as close to the bead,but not on the rim,as it will go. Start raising the vehicle and; 'why didn't I think of this earlier'. Job completed by Beer O'clock.