You shouldn't have to do anything if you have the ORBX Pacific Fjords installed. You should have an "FTX Central" application on your desktop. Make sure that is NOT on "Default FSX". It needs to be on "North America"
Then you can fly anywhere the ORBX scenery is on your system. For me that's "Pacific Fjords", "Northern Rocky Mountains" and "Pacific Northwest"
Return to Misty Moorings resides inside the "Pacific Fjords" region. So it's seamless.
Brad