It depends, here are your two options:
Epcot World Showcase to MKP - If you end your day at Epcot in WS you can exit via International Gateway (between UK and France), walk to Beach Club Resort, and take a WDW resort bus from there directly to MKP main entrance.. This is only effective if you happen to be in WS and near International Gateway..
Epcot Main Entrance to MKP - From Epcot main entrance, IMHO, monorail is the most effective way to get to MKP, yes there is a quick transfer at TTC but this is a simple walk from one side of the station up the ramp to the other and then you can board an express monorail to MKP.. Yes buses are available as well but IMHO the bus pickup area at Epcot main entrance is a bit of a walk from the gates and buses are of course subject to roadway traffic, etc. Not to mention it is not nearly as interesting as the monorail..