Just in case:
Skinning: Understanding A Template-Based System
What you can do:
- Make sure you have $debug enabled. (A tutorial can be found within the Articles section.) Some important information is available when you have this enabled.
- Set Add Template Name in HTML Comments to YES. (ADMINCP / vbulletin Options / General Settings)
- Test on a development board.
The vBulletin Manual has some good information regarding the Styles Manager.
http://www.vbulletin.com/docs/html/styles_and_templates