This thread should have some helpful info for you.

Here's the immediately relevant part, to get started:

Repotting:
First, I draw a major distinction between potting-up and repotting. Potting up can be undertaken at any time. It involves moving the plant to a slightly larger pot and back-filling with fresh soil, with a minimal amount of root disturbance. Much to be preferred to potting-up, is repotting. Repotting, which has a substantial rejuvenating effect, includes removing all or almost all of the old (spent) soil and selective root-pruning. It is by far the preferred method and probably the most important step in insuring your trees always grow at as close to their potential genetic vigor as possible. Repotting as opposed to potting-up is the primary reason bonsai trees are able to live in small containers for hundreds of years while the vast majority of trees grown as houseplants are lucky to survive more than 5 years without root work

It is pretty much universally accepted among nurserymen, that you should pot up at or before the time where the condition of the roots/soil mass is such that the roots and soil can be lifted from the container intact. Much testing has been done to show that trees left to languish beyond this point will have growth and vitality permanently affected. Even when planted out, growth and longevity of trees allowed to progress beyond this point is shown to be reduced.

The ideal time to repot a Ficus, is when the plant has good vitality and in the month prior to its most robust growth. June and July are prime months for most of the US. HOW to properly repot is beyond the scope of the initial post, but I am sure the subject will be covered in detail as questions arise.

Remember - potting up a root bound plant is a stopgap fix, and ensures the plant has no opportunity to grow to its genetic potential within the limits of other cultural factors; while fully repotting, which includes a change of soil and root pruning, ensures the plant WILL have the opportunity within the limits of other cultural factors. Strong words, but to repeat the illustration: the bonsai tree is capable of living in a tiny pot, perfectly happy for hundreds of years, while we struggle to squeeze 5 years of good vitality from a root bound plant - root work being the difference.

Thank you so much, I was afraid of pruning too much and unsure of what to do, this helps alot.