On payment in full of the purchase money, and the performance of the terms and conditions stipulated in the contracts, a declaration in writing to that effect may be made by the vendor, lessor or bailor or his assignee, on the margin of the record of the contract, duly attested, or by a separate instrument, to be acknowledged by the vendor, lessor, or bailor, or his assignees, and recorded as provided in La. Rev. Stat. 45:1242.