You have a beautiful specimen plant. I agree with Tom. Top and root prune. Root you top cuttings. I would not root prune drastically enough to reduce the pot size. Just enough to keep it in the same pot. Your Ficus will probably lose most or all of it's leaves but don't fret. Put it back in it's home. It will recover.
Looking at your picture - a larger pot is probably a good idea. The diameter of the pot compared to the canopy is out of proportion. The pot is too small.
Elizabeth - or Your Majesty
Living and growing in Lafayette, La.
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant. ~Author Unknown