How can i change my joint sponsor for the affidavit of support(i 864)?

The general answer is yes unless the matter was revoked due to the passage of time. You should have been notified about an expiration of the visa petition, if this is an issue. The first person can still act as a sponsor, but must provide proof of U.S. Citizenship or lawful permanent resident status. A joint sponsor must be otherwise eligible to act as a joint sponsor. Some may not qualify based upon past sponsorship or insufficient proof of assets. Recent Tax returns or tax return transcripts may be needed unless there is proper authorization to review IRS documents provided by the joint sponsor. You must have filed a U.S. Tax return or prove to the satisfaction of the USCIS that you somehow did not need to file a tax return, among other actions. This can complicate matters, as well. I strongly recommend that you schedule an appointment or teleconference with a candid and experienced immigration attorney. Such a discussion can provide you insight into the process. The above is general information not meant to be legal advice. The above reply does not create an attorney-client relationship.