You didn’t say what Norton program you are trying to remove. It may make a difference in how you proceed. Is it NIS? NSW? NAV?
I did read that “symantec” (without quotes) has always been the default uninstall password. Could be worth a try.
If it’s NIS you are working with, have a look at this solution:
http://service1.symantec.com/SUPPORT/nip.nsf/0/18f42370eefbccac88256e06005e17c4?OpenDocument&seg=hm&lg=en&ct=us
Good luck.