Sold one of two rental properties that have always been deeded together

Hello,

 

I have held two structures in an LLC since 2008 and they have always been deeded together (there have always been two addresses but for real estate purposes with the county it was on one deed, so one property tax, etc.); therefore, I reported the rents, expenses, taxes, depreciation, etc. as one entry on my taxes (noting that it was two structures that were deeded together). In September 2021, we had the property surveyed to divide the properties and sold one of the structures and land to the tenant (seller-financed). The land was divided in about a 60%/40% split with the 60% piece of land and the house that it contained being sold. How is the best way to reflect this on my 2021 taxes?