You will need to completely uninstall the previous version of the extension before you install the newest version. When you are installing the new extension you should select 'yes to all' if you get prompted to overwrite existing files.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.