How to repot a plant

I found out my friend has a plant today. He's scared of keeping it, so I'll be the new owner. The problem is he had it in a five gallon bucket with shitty dirt. It's about two feet tall. I would like to replant it in another pot, but I'm not really sure how I should.

Can I just take the plant out of the pot and then get all of the dirt off the roots with a water hose? Then just replant it in some fox farm.

i usually just hold the plants by the stalk/roots and shake it carefully knocking off a good portion of the dirt