As of Tuesday, January 12, six days have transpired since the President of the United States incited an angry mob to storm the Capitol, with many proffering chants to kill Vice-President Mike Pence. If Pence won't invoke the 25th Amendment over that, nothing will. The current path being explored for removing Donald Trump from office is impeachment. The House has already prepared an article.
If it makes it to the Senate, despite everything that's happened since Election Day, I don't see Joe Manchin and 17 GOP senators deciding to remove him. They could see it as setting a precedent more dangerous than leaving Trump in office to the end of his term, even with more threats of right-wing violence lurking. A second impeachment but lack of removal would mean that the President could run again in 2024 in an effort to be the second US president ever (besides Grover Cleveland) to serve non-consecutive terms.
An older Constitutional remedy would be Amendment 14, Section 3:
"No person shall be a Senator or Representative in Congress, or elector of President and Vice-President, or hold any office, civil or military, under the United States, or under any State, who, having previously taken an oath, as a member of Congress, or as an officer of the United States, or as a member of any State legislature, or as an executive or judicial officer of any State, to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof. But Congress may by a vote of two-thirds of each House, remove such disability."
It was passed to prevent Confederacy officers and officials from holding public office after the Civil War. Implementing this section against Trump would only require a majority in the House and Senate to declare that Trump has engaged in insurrection against the United States by trying to overturn a certified election and encouraging an angry mob to head to the Capitol and fight. If it passed, it would require a two-thirds majority in both houses of Congress to revoke it.
Not only could this be used against Trump and clear the decks for the 2024 Republican presidential primary, it could also be used to expel other culpable maybe-insurrectionists like Senators Ted Cruz and Josh Hawley or Representatives Madison Cawthorn and Mo Brooks. Again, the fear of establishing a dangerous precedent could be the main reason Congress does not do this, but if Democrats really want to prevent Trump from spending the next four years as his 2024 presidential campaign insisting the election was stolen, this is their best path.