I want to erase a dependent I claimed on my tax return
To do this, if you already filed and it was accepted, you must amend your tax return. https://turbotax.intuit.com/tax-tips/amend-return/how-to-file-an-amended-return-with-the-irs/L6kO691...
If your return was not yet accepted, you can just delete the dependent during the personal interview section.