Box hedge pruning and transplanting
Q1. Plant age should be taken into account when deciding when to prune boxwoods. Young plants actually benefit from frequent shearing. Your boxwoods are mature bushes and care must be taken to not trim them too severely at one time. The best time to trim boxwoods to shape is during the first few years. Severely pruning older boxwoods can kill the shrub. It’s best to take such drastic measures in stages, over several years if necessary, to give your boxwood shrubs the best opportunity to survive. Boxwoods can be trimmed at any time of year, but, for plant health, it’s best to avoid shearing in the late fall. The new growth that appears after trimming boxwood bushes may not have time to harden off before frost.
Q2. Generally speaking boxwoods do not transplant very well and they won't look very good for quite awhile until they fill out with new leaves. They are currently planted very close together and the sides touching the other plants will have very few leaves on them. However, large, well-established boxwoods can be transplanted if you can dig out enough of the rootball. With large plants, this is difficult for a homeowner to do without special equipment such as a tree spade, which leaves a large ball of soil intact around the roots. Most of the shrub's roots will be in the top 12 inches of soil, but roots may extend out several times the width of the shrub. It may help to make downward cuts a foot deep into the soil about 18 inches from the main stem one year before you want to transplant them.
Cutting through the roots like that forces them to branch and develop a more extensive root system close to the main trunk. Then the following year you can dig up the shrub and transplant it, attempting to keep as much of the soil in place as possible. The best time to transplant is either late winter (March) just before spring growth begins, or a couple of months (October) before the ground freezes in early fall.