I sold a company in 2015 and the stock I sold was set as a LT capital gain. Part of the sell of the company was a holdback that was paid in 2016 of 14K. How can I enter

I sold a company in 2015 and the stock I sold was set as a LT capital gain.  Part of the sell of the company was a holdback that was paid in 2016 of 14K.  How can I enter this 14K as a LT gain. I do not have a 1099-from the company  but need to report it.