Much confusion surrounds the need to submit I751 affidavits and how to write them. We explain and provide an I-751 affidavit sample.Step 1 – Specify whether one or both spouses will be completing and signing it. WARNING TO BOTH PARTIES: This Affidavit is an important document. You must fill out this Affidavit completely, and provide accurate information. Mail in the signed portion of the certificate to the court. Contact the court 7-10 days later.