Manage your Mac’s storage
1 Check available storage
Click on Apple > About This Mac. Next, click on Storage. Your machine may need a few moments to calculate the amount of available space. The result is displayed in a colourful panel.
2 Manage storage
If you don’t have at least 5GB available, click the Manage button. Click Store in iCloud to upload videos and photos. Click Optimise to remove watched iTunes content too.
3 Reduce clutter
If you need to free up more space, click Review Files in the Reduce Clutter section. Click on Downloads then go through and ≈- click to delete any files you don’t need.