Hi Tim,
Sorry, I forgot to mention that you should also copy the IdeaBlade.VisualStudio.OM.Designer.vsix file if so you can generate/regenerate your model.
To install the extension, simply double-click on it. (you will need to restart Visual Studio to use the extension)
To uninstall it (you'll want to do that when 'switching' DevForce versions) go to Tools >> Extension Manager... in Visual Studio, select DevForce EDM Designer Extension and Uninstall.
Regards,
Silvio.