Winter-spring is a good time of the year for moving the plant. It is cool, and the roots won't get too much stress from over-heat. Make sure it is not too cold, at least 50-60F. Otherwise, wait till it gets warmer.

Water the soil around the plant really well. Soak it. If the soil is dry, it may just toss of the roots - this will damage the root system. Make at least a circle 1/2 ft away from the crown side. Go deep with the shovel. As deep as possible. If the plant is very big, ask 2-3 people to help you with several shovels simultaneously. Once you take out the root ball out of the ground, you may place it on a piece of plastic and drag it to the new place. Make the new hole bigger than the root ball. Fill the bottom with well-drained soil (if you can
afford it, buy a potting mix from Home Depot rather than 99 cent top soil). Do not put any fertilizer yet. You will add it later when you see a new growth. Place the root ball in a new hole so the growing point is exactly the same level with the surface as it was before. Too deep - the plant may die from stem rot. Add more soil around. Water a lot - several times. Then, water every day and be sure root ball is moist at all times for 1-2-3 weeks until you see a new growth. Then rely on regular watering or sprinkler system.

If you notice leaves drooping, you may put a large clear plastic bag over the foliage for 1-2 weeks. Make sure the plant is protected from winds and cold. Use covers if needed. If frost occurs, you may place a candle or Christmas light inside the cover (be careful not to cause a fire). We have some experience with moving large plants. When we sold the house, we had to dig out many of them to save from the new coming owner who hated plants. :-) All of them made it and are now living in pots (5 months already), expecting to be planted at our new place. And yes, I did trim some of them AFTER we potted them - to reduce stress (less leaves - less eveporation). But not much, especially when it's not hot. It is not necessary if the root system is not damaged badly.

You may also try to apply growth hormones like Epin, it helps to recover from stress.