Use tire "spoons" if it came completely off the rim. If the tire is still on the rim, but the bead is off the rim, use a dish soap and water to lube the bead and rim. then use ratchet straps around the tire tread to cinch it in so it seats. Take the valve stem out and air it up.I have done it with tyre levers and screw drivers, it was not fun to do at all, but i got there.