Is there a legal document I can obtain to be left out of someone’s will?
I want to be left out of my father’s will, if at all possible how do i do that? I have no qualms about accepting any debt he has but I don’t want to gain anything from his death. Thank you for your help.

The affidavit is the purest form of law.
Submit your affidavit to all parties concerned, be sure to delineate exactly what you hold to be true and what facts you want all the others to accept. Provide a time-frame for them to respond by rebuttal, 30 to 90 days is customary.
If you get no rebuttals to your affidavit, all your assertions become truth in law, fact and commerce as pertaining to those served (certified mail is sufficient) with your affidavit of truth.
You can’t but you can renounce the inheritance after he dies; in that case, the money will go back to his estate.
tell your dad to name me as the beneficiary in your place, i will accept his debts and profits!!