unpack the zip file directly to your main EverQuest2 folder and say yes to all. 
But since your reading this you have already unpacked the folder.

if you unpack the file then..
1- copy & past the eq2.ini file to your main EverQuest 2 folder.
2- open the UI folder and copy the daimond folder to your UI folder.
	or copy the UI folder to your main EQ2 fold and say yes to all.
3- there is a folder with in daimond folder that contains a few .xml files for a smaller EXP. bar for 1024x
resolutions also 2/3 maintained & effects. if you want to use these files.
copy then to you daimond folder and over right a few of the files there.

when done start your game and you got a new UI.

added some extra background files, to change your background go into the folder daimond/images 
and rename one of these files....

daimond_background_paper.dds
daimond_background_darkblue.dds
daimond_background_gray.dds

to the defualt background called daimond_background.dds and you have a new background.
although make sure to rename the defualt to something new incase you want to goback to that one.
this will also change the background of other backgrounds made by me as well. To make a black Background 
delete or rename daimond_background.dds