When installed, this addin registers a new command ("Open with Vim") but doesn't put it in any menus or toolbars for you. You can add it to a menu or toolbar by using Tools/Customize, go to the Commands tab, select Addins in the left listbox, and scroll down to find "Open with Vim". Now drag that to a menu or toolbar. Now open a file in VS.NET, move the cursor if you like, and click Open with Vim. It will launch vim and execute :drop for the file you had open in VS.NET. It then moves the currentpoint for vim to the same row and column that you had in VS.NET.