If the issue is one that should be addressed by the latest release of 4.5.1 then you could manually have it uninstalled by deleting your configuration folder. Here is a link to a troubleshooting guide that a Community Expert has written up that explains how to delete this folder to have it be recreated by Dreamweaver. This will have result in the currently installed extensions to be removed. You will need to make sure you open the extension manager and remove any remnants that remain.
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