The default password for the enforcer appliances can be found in the below articles, along with some troubleshooting steps:
http://www.symantec.com/docs/HOWTO81740
http://www.symantec.com/docs/HOWTO81703
Alternatively, it might be quicker to reimage the appliance and start again:
http://www.symantec.com/docs/HOWTO81662
I've not found any articles that discuss how to recover a lost appliance password.