I assume you mean taking someone off of the deed to a property and adding another party to the document. The person coming off will have to sign a deed transferring the title (ownership) to the other party. There must be consideration (something for something), which can be $1, love and affection or other valuable offering. The deed can be a quit claim deed or even a warranty deed.
You did not provide enough details for me to know the entire circumstances, but you might want to consider a Lady Bird Deed. Click on the link below to learn more. It really is a great way for someone to take title.