If the spores were introduced externally, removing the top couple of inches of soil and replacing may help. If they showed up after adding in compost/soil etc, it's very likely that soil was contaminated and the above method won't work and the best bet will be to replace all the soil. If you're diligent and carefully remove the caps as they develop you'll cut down on new spores. I'd remove a couple inches of soil, apply your o. fungicide, add new soil, check it several times a day for growth and see how it goes. If they continue to come back then look to replacing all the soil.

The mushrooms came from an outside source. I think I will try removing the caps and a fungicide thank you!

I had the same problem in a houseplant that I ordered from a nursery in FL. I did not want the spores spreading to my other plants. I removed all the soil and repotted the plant in a mixture of hydroton pellets and coffee grounds. I discarded the soil and the pot entirely. All my other plants did not show any mushrooms so I figured it had to be in the soil of the one ordered online.

I doubt there's much you can do to completely be rid of it. If a mushroom opens, then the spores are EVERYWHERE. Picking it or fondling with it may release more, but if it's already open then it doesn't matter. It's not gonna hurt anything to leave it and even if you try changing the potting soil, chances are that you'd see it pop up again. Best option is if you really MUST be rid of it, just pick them as they appear and throw it away.

I just leave them alone. The heat, and direct sun will kill them. Besides none have done any harm to the plants I have grown. In the garden they help with breaking down organic matter to release the micro nutes contained in it.

Mushrooms are usually a good sign. Things are happening inside your soil as it should!