I am not sure if that would work or not. It sounds like you might need to install the License Manager by itself in order to uninstall ED.
Do you have a current COBOL Server product on maintenance? If you do then you can go to our product updates site and download the COBOL Server Deployment Toolkit from the COBOL Server 2.2 section. This is a zip file that contains the license manager installer lmsetupx86.msi.
There is also a KB article that explains how to extract the license manager installer from the 2.2 product here:
Installing this may allow you to uninstall the previous products.