Putting him on the deed is simple. Just record another deed, from you to you and him.
Getting him on the note, would require that it be rewritten I guess. Don’t know if the maker of the note will want to do that, especially if had to qualify in any way.
I just bought a house using a mortgage company and I just got a business partner and we need to put him on the warranty deed. How can I put my partner on the deed and also make him partially responsible for the note?