Prune back the vine once all threat of harsh cold weather has passed, or in early March, as recommended by the University of Rhode Island. Heavy pruning is recommended prior to transplant, so the vine may focus on supplementing nutrients and not desired growth. Water the vine heavy, because the roots will not absorb water for several days after the movement.
Dig up the roots of the vine, keeping as many damage-free as possible. The older the vine, the more likely you will lose some roots or damage ones that are widespread. For roots that cannot be cleanly dug free, use a large, sharp knife to slice through the root as straight and clean as you can. Ragged tears and mauling the roots will cause stress that can wilt the vine.
Dig into the new site until you have a hole large enough to encompass the root system without bending or breaking any roots. This depends greatly on the age of the vine, but you may experience a hole at least 12 inches deep and possibly 12 inches wide. Loosen the soil within the hole until you are sure the roots will easily push through while growing.
Place the roots of the vine into a container of water for at least six hours. This will help moisten the roots and ensure that the vine has enough water content throughout the branches while the roots are in shock.
Set the roots within the hole and cover them with soil. Placing fertilizer directly into the hole can kill your roots, as my-grape-vine.com explains. Allow the vine to come out of shock before treating or spraying it with any type of nutrients or insecticides. Root shock will not last longer than two weeks.