If you have FileMaker Advanced, you can launch the application without opening the file, enable the script debugger and then open the file from the File menu. When the startup script's first line pop's up in the debugger, you can click the red X button to kill the script.
If you do not have FileMaker Advanced, you can create a new database file and create a script in it that uses Perform Script to perform some other script in your original file. When you perform this script in the new file, the original file is opened in the background without tripping the script trigger and then you can get to the file and modify the script or the file option script trigger that performs it.
That is a wonderful solution. We have FM12 Pro, not Advanced, so this would be a solution and I can imagine (unconfirmed) it would work perfectly. I was able to find a workstation that still had the DB open and that user had admin priv. I edited the script on that computer and we are back.
Thank you for the help!!