In vbulletin Options, General Settings, select Yes in the Add Template Name in HTML Comments section. Save ...Don't forget to change this to no when you are finished.
Now, view your site, right click on any white space on your site, select view source, search for some of the code I posted.... above it, you will find the template name you need to edit.
--------------- Added [DATE]1400604022[/DATE] at [TIME]1400604022[/TIME] ---------------
If you still cannot find it, set me up with an admin account with full permissions, pm me the info & I will have a look.
--------------- Added [DATE]1400605224[/DATE] at [TIME]1400605224[/TIME] ---------------
You will need to edit this file for the navtabs via FTP.
Looks like you have a second header template named SdHeader , look there.