Where can I manual edited the template files?
 

Where do these files exist in my server if I want to edit them manually (not through admincp)? Say I want to edit header template... Where is it in my server?
Basically I messed something up in one of my files and i have a backup and want to overwrite the header template...

Thanks so much guys!

They are in the database - they are not files.

If you have a backup, copy the source from the backup and paste it into the 'header' section of the style in question in the style manager.

You can edit them manually from your MySQL database, but it would have them same effect.

Using the AdminCP is the only recommended method of editing a template. Otherwise you will bypass important processes which vBulletin does to templates and so may cause even more problems for your site.