Hello,
How to manually uninstall Symantec Endpoint Protection client from Windows 2000, XP and 2003, 32-bit Editions
http://www.symantec.com/business/support/index?page=content&id=TECH102261
OR
If you don't have any uninstall password change registry setting.
HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\Symantec Endpoint Protection\AV\AdministratorOnly\Security\UseVPUninstallPassword
Set to 0 to disable
OR
You can use Symantec Cleanwipe Utility. To receive the Utility, you need to contact Technical Support.
Check this Thread which have same query -
https://www-secure.symantec.com/connect/articles/how-uninstall-symantec-endpoint-client-if-uninstall-password-place
and this Article -
https://www-secure.symantec.com/connect/forums/sep12-requires-uninstall-password-was-never-set
Hope that helps!!