The 25th amendment is for when a President is temporarily unable to perform his duties. It makes the vice-President the 'Acting President', it is NOT a permanent removal.
His cabinet could 'remove' him, but all he needs to do is to write a letter to the senate saying that he is resuming his duties and he will be back on the job.
It would take a vote of 75% of BOTH houses of Congress to keep him from resuming his duties...even then the Vice-President remains an 'Acting President' only.
Try reading the amendment!