The process for installing fonts differs for each operating system. Installation instructions are given below for two of the most popular platforms, Windows and the Mac OS.
Unpack the zip-archive containing the fonts into a temporary folder.
From the Start Menu, choose Settings and then choose Control Panel.
From the resulting window, choose the Fonts folder. A separate window will appear displaying all the fonts presently installed on one's system.
From the File menu of that window, choose Install New Font.
From the Add Fonts window that then appears, choose the drive and navigate to the temporary folder where the font files have been unpacked. The list of available fonts should then appear.