Basically you need to unpot the plant, rinse off all the foliage and remove the fertilized dirt from the plants roots. Then rinse the roots and plant in your substrate. Some people just rinse the plant in its original soil and bury that soil into your substrate and ensure that soil is below your top layer of substrate.

You should ID the plant to ensure i is suitable for your frogs since some plants are not. Umbrella plants are a good example as are arrow plants. Both are toxic and can create issues with some frogs.
You can post a pic and someone can ID it for you.