[Vigilanteman]

The only Constitutional method for the Legislative branch to remove a President is impeachment by the House and conviction by the Senate.

Not only. See my link at Post #42.

This method is actually more difficult, however, since impeachment only requires a majority vote of the house and conviction a two-thirds vote by the senate.

The alternative method requires a two-thirds vote by both houses.

[Bubba_Leroy]

The 25th Amendment requires that the Executive branch (either the President or the VP and a majority of the cabinet) decide that the President is unable to discharge his duties.

The 25th Amendment was used for very brief periods of time by both Reagan and George W. Bush when they were temporarily incapacitated for surgical procedures.

Congress only has the power to step in and decide that a President is incapable of fulfilling his duties under the 25th Amendment if there is a dispute between the President and the VP over whether or not the President is capable of discharging his duties (i.e., the President says that he is capable and the VP and Cabinet say he is not).

Impeachment is the only method for the Legislative branch to remove a President without first being requested to do so by the VP and a majority of the cabinet.