How to -> Visual Studio Add In Manager

How do I use the Add-In Manager in Visual Studio? Here is the problem and solution.

I want to add this SmartPaster addin and need to get these 3 files listed in the Add-In Manager dialog?

1. SmartPaster2010.AddIn
2. SmartPaster2010.dll
3. SmartPaster2010.xml

Edit: Microsoft Add-In Registration says:

To install the add-in on another computer, the .addin file must be placed in a location where Visual Studio checks for add-ins. These locations are listed in the Options dialog box, in the Environment node, on the Add-in/Macros Security page.

I went to Tools > Options > Environment > Add-In/Macro Security, checked some paths put the AddIn files in a couple of these directories, restart VS2010 but still no luck!