Dig around the circumference of the drip line. Cut off as little of the roots as possible. Dig the new hole 1. 5 the width and 2. 0 the depth. Put the plant in. Fill the hole 1/3 and put water up were you filled. Repeat the process until you're done.
It is a two-step manipulation. First this fall you need to prune the roots of the holly bushes, using a spade to section the roots around the bush. Then next spring, you can uproot the bushes with a large enough root ball.