Someone said :
So, how will Donald J Trump's (first) term of office end?
There is no such thing as "Removal under 25th amendment" though...
The term is used abusively (including in authoritative circles): it should be "replaced".
The amendment does not provide for the removal of the President, but for what happens in case she is removed, and then for other things.
Section 4 defines the procedure to determine if the President is unable or unfit. But that is not a removal!
(Section 3 is about the President declaring herself unfit, until she declares herself fit again)
He can only be "removed" by Impeachment + Conviction
The correct term relating to the 25th Amendment would be "replaced"... due to "Inability to discharge the Powers and Duties of his Office"... until he gets better or another President is elected.