Dig your hole. Make it wider and only slightly deeper than the size of your pot. Water the hole and let it drain. Remove the plant from it’s container and loosen the roots. If the plant is very root bound use a fork to loosen. Place the plant in the hole and back fill with the soil that you removed. Fill to the same level as the plant was in the pot. You want to create a slight well as it will be easier to water. Fill the well with water, let it drain and repeat. Place mulch all around except for the very base of the plant.