I would do as stated in an earlier post-repot pot in pot! I like using terracotta pots because they breathe and the roots love them, but they are expensive. Just get a larger pot and shove the old pot with the plant in it, into the new pot. Fill with bark/medium of choice. It works a breeze, and i have had success with pots like yours and this method. It reduces stress on the plant and they can keep growing, unlike the three phals i repotted that were like yours is with the roots, where i accidentally skewered the roots (trying to be as careful as possible), and that was a year ago, and they are only just starting to grow new roots and a new leaf.