First, the day bfoere the operation, water the tree really thoroughly. Then prepare the planting hole for where you want to move it to. Dig it nice and large and add some compost and bonemeal etc. Next day, dig the plant out with as much rootball as you (and a strong freind!) can manage. You could heave it onto a tarpaulin and then drag it over to the new site. Replant it to the same depth as before and heel it in firmly. Water copiously and remember to water it all summer long, even if it rains.