Self-employed

Hello: Maybe I'm doing something wrong, but I cannot make these instructions work in Turbotax 2019 because I cannot overwrite the pre-calculated CCA claim for the year. Can we try one more time?

Assume I have a class 50 asset with an opening UCC of $1,000. This was the final year of my business and I want to zero out the UCC at the end of the year. Proceeds of disposition were $750. Therefore I have a terminal loss of $250. How do I reflect this in Turbotax 2019 and force the UCC at year end to be $0? Thank you!