i downloaded the file but i have no idea how to put it on my iPhone any help would be appreaciated
I would suggest getting PowerTool from Cydia. You will need it to respring your phone after installing.
1. unzip the Customize 2.1.1 file.
2. SSH to your phone (WinSCP etc)
3. Copy the file to the Applications directory.
4. Right click and goto properties of the Customize folder. Change the permission to 0777.
5. Go into the Customize.app folder and change the permissions on "Customize" and "Customize_" to 0667.
Hard Respring your phone with PowerTool. And You should be good to go. I still haven't gotten around to playing with Customize yet. I don't know what problems you might run into. I used this method to get it installed and working.