I picked this plant up at a store this week. I brought it home and found it so pot bound it was sitting like a loose rock in its pot! It had pulled all the dirt in the pot into a tiny ball it was so pot bound.
The first thing to do with a pot bound plant like this is get it out of that pot and soak it. This one soaked for an hour and still the dirt/root ball was too stiff to loosen.
If after soaking your plant you can very gently and slowly loosen up the root ball do so.
If you can not loosen the root ball take a very sharp, very clean knife and make 4 cuts, one on each side, from the top of the root ball, to the bottom about 1/4″ deep. This will allow the new roots to grow out instead of continuing to circle which would in time strangle the plant.
Once the roots are loosened or cut you can repot this plant in a larger container with some fresh potting soil.