There are a few ways to do this, but here I pinned down the easiest for the most popular operating systems.
Windows 10:
• Unzip the folder containing the fonts first.
• Right click on the font file and select Install. That’s it, enjoy your font!
OS X (Mac users):
• Unzip the folder containing the fonts first.
• Double click the font file and the Font Book application will open with a preview of the font.
• Click Install Font at the bottom of the preview