To delete a line item for depreciation, go to Deductions > Depreciation, and click on the trash can icon on the far right of the asset you'd like to delete.  This will remove the asset altogether, no depreciation for the year will be computed, there'll be no trace of the asset, needless to say that the asset will not be proforma'ed to next year.

If you enter 1=delete this year, the asset will remain on record but no depreciation will be computed.

If you enter 2=delete next year, depreciation will still be computed for the current year but the asset will not be proforma'ed to the following year.

You may also like to refer to this article for how entries should be made when assets are being disposed of: https://proconnect.intuit.com/community/form-8949/help/entering-a-sale-or-disposition-of-assets/00/5...