If no principal payments were ever made on the first sale, then you can just ignore the first sale.  Just treat the new sale as usual.

Or do you have questions about how the 'usual' sale is reported?  If so, your first statement indicate a sale of the "garage" on "land contract", which seems to imply it was just the real estate that was sold.  But then you mentioned the recent sale was a "business".  If you have questions about how tor report the sale, you may need to clarify what EXACTLY was sold