Right-click the font file(s) and choose "Install".
For users of the previous Windows versions:
Copy the included file(s) into a default Windows font folder
(usually C:\WINDOWS\FONTS or C:\WINNT\FONTS)
For Mac users:
Mac OS X 10.3 or above (including the FontBook)
Double-click the font file and hit "Install font" button at
the bottom of the preview.
Mac OS X
Either copy the font file(s) to /Library/Fonts (for all users),
or to /Users/Your_username/Library/Fonts (for you only).
Mac OS 9 or earlier
You have to convert the font file(s) you have downloaded.
Drag the font suitcases into the System folder. The system
will propose you to add them to the Fonts folder.