Juniper trees are nice additions to many yards and add interest to the landscape or can be planted closely together in multiples for privacy, especially along property lines. Transplanting any tree is risky, including junipers. The younger the tree, the more likely the transplant will succeed. The best time to move junipers is in the fall, before the first freeze.
Choose a new location that is exposed to the same amount of sunlight as the juniper is currently used to, probably full sun to partial shade.
Dig a large hole at the new site. It is best start digging the new hole before you dig up the Juniper so you can transplant it right away. Estimate how big the root system will be. In general, your new hole should be two times as wide as the root ball, but just as deep. You can always dig it out wider later, so estimate on the small side.
Amend your soil. With the soil you just dug out, mix in one-third organic matter such as compost or peat. You will use this as the back fill.
Dig up your juniper. Start out wide, about 1 foot away from the base for a small juniper tree, or a couple feet for a large juniper tree. You may have to do some exploring with your shovel to see exactly how wide the roots spread. You will have to cut through some roots, but try to keep the main root system intact, if possible. Dig just deep enough to get the bulk of the roots.
Lay the tree on a tarp if you can not physically move it yourself. Drag (on the tarp) or carry your Juniper tree over to the new hole and dig it out larger, if necessary. Backfill some soil in if you dug the hole too deep. Remember, it should be just deep enough for the roots, but twice as wide.
Put the tree in the new hole with as much root and soil from the previous hole. Be sure the trunk is straight. You may need a second person to help you.
Back-fill the soil in and water well. Tamp the soil down to minimize air pockets. Use root stimulator, if desired, which is available at you local nursery. You can also prune the tree a bit to help compensate for some of the root loss. You do not need to fertilize a transplanted juniper tree.
Keep your Juniper well watered for at least one growing season. However, do not over-water it, which may cause root rot. Adding a couple inches of mulch after transplanting will help retain water.