1) Make a folder named myui
2) Un-zip the ui mod into this folder
3) Move the folder to <eq2 directory>/ui/
4) In <eq2 directory> (not your UI folder) make a new text file
5) name it eq2.ini
6) open eq2.ini in your favorite text editor
7) add this
cl_ui_skinname myui
cl_ui_subdir UI/
Go in game and enjoy your new ui adition.
Now use
search on the forum as there are alot of threads covering this exact same topic.
Like these
http://www.eq2interface.com/forums/showthread.php?t=293
http://www.eq2interface.com/forums/showthread.php?t=304
http://www.eq2interface.com/forums/showthread.php?t=290