asp.net mvc - Integration from MVC2 .net 3.5 to MVC3 .net 4.0 -

like know step need integrating mvc2 .net 3.5 mvc3 .net 4.0 without using upgrading tool.

the thing should require .net framework upgrade on box serving iis. mvc2 .net 3.5 app should work seamlessly side-by-side mvc3 .net 4.0 app.