Even if they take out both senile Joe and Scamala, the Presidential succession act will apply.
VP, then Speaker of the House, etc. Only way to go directly to Trump, would be to have him become Speaker, and the Demoncrats, who will be pissed, take out Scamala.
Doubt any of this is going to happen. If Potato croaks, the Dems will likely pull in a clone (ala the movie "Dave,") and just let the people who have been pulling the strings in the background keep doing it.