To install Lith-O-Hell you must already have Quickeys™ installed on your Mac.  If not, you must install Quickeys™.  If so, follow these steps to complete the installation of Lith-O-Hell:

Step 1:  Place the Lith-O-Hell keyset into the Quickeys™ 
         Keysets folder, which is located inside the 
         Quickeys™ folder inside the Preferences folder.

Step 2:  Place the Lith-O-Hell sequences into the Quickeys™ 
         Sequences folder, which is located inside the 
         Quickeys™ folder inside the Preferences folder.

Step 3:  Open up Quickeys™ from the Apple menu.

Step 4:  Select "Open Set..." from the File menu in 
         Quickeys™ and open up the Lith-O-Hell keyset.

Step 5:  Press cmd-A to select all of the sequences from 
         Lith-O-Hell.  The press cmd-C to copy all of those 
         sequences to the clipboard.

Step 6:  Go under the "Sets" menu in Quickeys™ and select 
         the first one, called "Universal."

Step 7:  Press cmd-V to paste all of the Lith-O-Hell 
         sequences into the Universal keyset.

Step 8:  Press OK, and you're done!