Hi There and Welcome to Fixya.
I see that you need to "sync" your MAC with your Bushnell Yardage pro for you to upload your downloaded courses. The only way for your MAC to communicate with the GPS is to download this application that will sync the 2 devices :Bushnell Sync
Check the bottom of the screen after clicking on the link and choose the "SYNC APP" tab (shown below):
Then choose and click the one for Mac, download the installation files until it's complete.
After the installation, run the setup file and you should be able to connect the GPS with your Mac afterwards. The link also has some helpful tools and FAQs.
Hope this helps,
Thanks for using FixYa.