Here's the post that helped me: http://www.computing.net/security/wwwboard/forum/20289.html
It worked for me using the Corporate Edition Version 8.
For reference, here's a copy:
To remove / reset the uninstall password for Trend Micro OfficeScan
Edit Ofcscan.ini file. (Do a search.)
On Windows.95/98/XP machines it is usually in C:\Windows\Ofcscan.ini
On Windows.NT/2K machines it is usually in C:\WINNT\Ofcscan.ini
Open the Ofcscan.ini file using notepad search for the [INI_CLIENT_SECTION]
Find the line reading Uninstall_Pwd= and type a # at the beginning of the line to comment it out.
Insert a new line saying Uninstall_Pwd=70
Save the Ofcscan.ini file and retry the uninstall. When it prompts you for a password, enter a '1'.