Water the rose deeply -- to at least 12 inches -- the day before root pruning.
Use the spade to dig into the soil, 18 inches away from and completely around the rose bush. Insert the spade into the soil, angled toward the shrub and cut through the roots. Replace any soil that is disturbed during the process and wait at least one month -- two is better -- to dig up the rose.
Insert the spade into the soil in the same area created when you root pruned. Go completely around the shrub, angling the tip of the spade toward the bush.
Pull the rose from the soil by the main cane, at its base. If there are still large roots anchoring it to the soil, cut them with loppers. Shake the soil off the root ball.
Prune all canes back to the same length as the roots. For instance, if the roots are 10 inches long, cut the shrub back so each cane is 10 inches in length. This keeps the plant from going into transplant shock, trying to provide water and nutrients to a larger mass of foliage than the smaller root ball can support.
Pull off all foliage. Use your hands rather than shears.
Transplant the rose immediately to avoid the roots drying out. Water deeply -- to at least 10 inches -- and keep the soil slightly moist while the rose bush establishes in the new location.