G, I just go to the Mega folder, right mouse click on the file I need and click on standard download, then you don't have to unzip the file on your computer.
open your downloads folder on your computer, the file you downloaded will be in there, right mouse click on the file and click copy. open your PG folder where you keep your courses, scroll down to the recorded folder below that right mouse click on it and click paste C:\Program Files (x86)\Steam\steamapps\common\Perfect Golf.
I have made a shortcut on my desktop for the course folder so it makes adding new courses/recorded rounds easier to do.