With the threat of impeachment and with that the threat of conviction and prevention from holding federal office imminent, resigning could be an effective way for the President to avoid these problems. If the House of Representatives were right about to impeach the President, could they resign immediately or would some paperwork prevent that?
Is there any legal procedures the President has to follow to resign or can they do it immediately?
A letter of resignation is required.
The only evidence of a refusal to accept, or of a resignation of the office of President or Vice President, shall be an instrument in writing, declaring the same, and subscribed by the person refusing to accept or resigning, as the case may be, and delivered into the office of the Secretary of State.