wait until it is dormant in the fall............dig the new hole first and amend that soil..........fill the hole with water...................trim back the rose bush to 18 inches...........use a very pointed shovel and go about a foot from the roots and dig out the root ball all around it...............use an old rug or heavy plastic to drag it to the new place............replant put some new mulch around it giving it room to breath and see if it needs more water. ph for roses is 6.0-8.0