should have done that before they reached 2 inches. But basically you need to tap the pot several times, loosen the dirt, then slip the root ball and dirt out, try to find the center root of each plant and carefull pull them apart, you can break the roots if need be, they will grow again. After that, quickly repot them in fresh soil then give a nice watering, hopefully they will set and within a few days they will be back to normal. Actually it's not that hard or invasive, plants are extremely versatile and will always find a way to survive.
Good luck