For Windows

  1. In Windows Explorer, go to the folder containing your fonts (TTF or OTF files)
  2. Select All (CTRL+A) for all these font files
  3. Copy (CTRL+C) for all these font files
  4. Navigate to Fonts folder in Control Panel (Start > search Fonts > first option that shows up)
  5. Paste (CTRL+V) into the Fonts folder

For Mac

  1. Open Font Book application
  2. File Menu > Add Fonts > locate folder containing your font files (TTR of OTF files)