Garmin 540 custom map, how do I enable it?

I just received a garmin edge 540 and I have updated it as well as updated the maps on garmin express....I live on Maui, hawaii and notice my street is blank, I live on a old street that has always been here....

I downloaded a file of the area I need from bbbike.org and have the file 'gmapsupp'  which I have copied the file to my edge 540 /garmin folder....

How do I enable this file in my device?  The youtube video skips the navigation to enable the file...All I see is the same gps map with my blank streets in my device...