The 25th Amendment is the easiest route for removal of Trump!
However, invoking the 25th Amendment also comes with enormous risk, that risk being Trump could responsively ignite a near-immediate escalation of the War on Syria. To protect his skin, Trump won't care if people die!
Trump knows, and history has proven, that neither political party or the media will tamper with a president engaged in an active state of war.
In order to invoke the 25th Amendment a deal must first be struck with the Pentagon for it to refrain from launching a full scale attack on Syria (i.e., Russia).