Seller Financed Mortgage

I am in the process of completing my 2024 taxes using the online version of TurboTax Premier.  I sold acreage a few years ago and receive interest payments each month from the buyer.   Those interest payments have been recorded as interest income (1099-INT).  The buyer has now paid the interest and principle in full in 2024.  I will enter the interest as income, but how do I record the principle balance that was paid?  It is noteworthy to mention that the acreage that was sold did not have a mortgage, as I inherited it.