First, I am not sure there is a bus from Epcot to the MK. Someone will know for sure. Secondly, it depends on where you are in Epcot. From the main entrance (Future World) you can hop on the monorail to the TTC and switch to the MK monorail. If you are in World Showcase you can exit at the International Gateway, walk to the Beach Club (about 5-10 minutes) and take the bus directly to the MK from there.
Note that the resort monorail will take you to the Contemporary Resort while the bus will drop you off at the MK main entrance. From the MK you can either take the monorail or a short walk to the CR for Chef Mickey's.