Because of space limitations, you may not want to transplant a large floor plant to a bigger pot. In this case, you can root prune the plant and put it back into the same pot. Root pruning might sound like a harsh way to treat a houseplant, but it’s actually a kind way of keeping a plant in check and allowing it to grow in your home.
After several years of growth, many large floor plants get tall and may threaten to hit the ceiling. Root pruning allows you to keep a plant at the same size and still maintain its health.
(HealthyHouseplants.com)
How much you prune will depend on the size of the plant and your goals. If you are trying to get the plant to stop growing and remain in the same size pot, you can remove up to one-third of the old roots with no damage to the plant. Cut away roots with a sharp knife or a small saw, removing the same amount of roots from the sides and bottom of the plant. Try to make clean cuts, as jagged ones can invite disease and decay.
Next, with a pronged hand cultivator, pencil, stake, and/or your fingers, loosen soil from the rootball and discard. This is generally saturated with harmful mineral salts and should be replaced. Doing so also coaxes the roots to grow out into the new soil more quickly.
Before repotting into the same pot, thoroughly clean and rinse the pot to destroy any disease and remove salt deposits. Use a stiff brush and a hot solution of nine parts water and one part bleach. Rinse thoroughly. Repot as you would any other plant.