Blueberries, like other members of the rhododendron family, have very shallow, fibrous roots that spread around the plant like a pancake.
That makes them really easy to transplant. Simply dig around the base of the plant to see where the roots are - start out and gently work in. Once you have the diameter figured out, dig in a circle around this outer limit of the roots. Then you want to cut in beneath this pancake of roots, trying to cut off as few roots as possible. You can do this by digging a wide trench and then angling your spade in underneath the root ball. Eventually you will loosen the plant enough that it will wiggle or rock in the soil. Then you can lift the whole plant gently and put the root ball into a plastic bag so it stays moist. If you can't replant the blueberry bushes right away, keep the plants out of the wind and keep the roots moist. If the weather gets below freezing, the plants would be happier in the garage so the roots don't freeze. When you replant them, water them well. Sometimes it's worth monitoring the soil for moisture even in winter. Dry winter winds can suck all the moisture from the soil which would be an added stress on a recently transplanted shrub. If we don't get some precipitation for a month, it wouldn't hurt to pour some cold water over the root area to keep the cold air away from the roots. And keep plants well-watered during dry periods next summer as well!