No it's not. SCOTUS can't remove a sitting President.
They can only find that he is guilty of transgressions which would cause the House to act to bring charges.
Then what?! Then nothing would happen.
That is true, but
No Person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President.
If he's not eligible, he is not, and never was, President. He would be illegally occupying the office. Impeachment by the House and removal by the Senate is for Presidents, not usurpers illegally occupying the office in violation of the Constitution.