Mar 20, 2019 One such situation is when wanting to run Windows 10 natively on your Mac (in my case my Mac mini). The 'normal' method would be to use Boot Camp to repartition your internal hard drive to make room for Windows 10. However, in some instances, repartitioning may not be an option. Connect the external hard drive to your Mac. Launch Disk Utility (press Cmd + spacebar and start to type Disk Utility). Before this next step - if you are running High Sierra or later you will need.
You should never get too low on your hard drive space as the OS needs a minimum 10 - 15 GB of empty space at all times to function properly. As well, if you do any movie or photo/image editing, rendering and editing works best if you have at least as much empty space as you have temporary files in your project; I can easily amass 100 GB or more of temp. files for a one hour HD movie, so I keep a lot of hard drive space empty.
So, in order to get some stuff off your hard drive, the usual space hoggers are movies, photos, etc. You can move all of those in their library to an external hard drive and, after making sure they work there, delete them from your hard drive.
In general, application work best if they are installed on your internal hard drive; I am not a gamer, so I am not familiar with the specifics of the game you are referring to. Googling it, I could not find any reference to Macs on their website - here it shows the platforms it is compatible with: