Use the following to disable password and remove the product.
1. Open the registry
2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\Symantec Endpoint Protection\SMC
3. Change the value for SmcGuiHasPassword from 1 to 0
4. Restart the SMC service
Then uninstall the product :)
NB: if its SEP 12 there is no password option for uninstall protection
It seems you have some GPO applied for this particular product or exe file check with GPO