juniper parsonii

Hi it's Steve from Naples. I have a juniper parsonii that I found at a local nursery. It is so root bound that the plastic pot is bowed and probably restricting the plant from growing. I've had it for 3 months and it is just maintaining with a few new shoots coming off the trunk. Can I do a partial root prune at this time of year to relieve some pressure. I want to reduce the roots over time but how much time. Any thoughts?

Here in this part of the U.S. during the warmer months of the year,  we don't mess around with the roots on our junipers.  Too much stress on the tree during these hot growing summer months. But, I'm not sure how 'seasonal' things get that far south....  does it even get freezing cold there?
Here further up north, its almost always best to wait on performing root work until early spring, when the junipers are just starting to emerge from near domancy in the winter.  So, if you have at least a cooler winter-time season, I would at least wait until your local conditions have cooler, less stressful temperatures then to work the roots and re-pot your juniper.

It seldom freezes in Naples, but still, the best time to work on roots is fall or spring. I'd simply find a larger (diameter) pot of the same depth (cut one down if needed) and put the tree in that until a better time for root work.