You just have to open the project in Visual Studio 2010. It will offer you before it is updated. I recommend making a backup (there is a checkbox in the upgrade wizard). Just follow the instructions of the wizard. It is pretty simple.
/. .net 2.0 3.5, . , 4.0, . MVC 1.0 .net 4.0 renderpartialtostring. , 4.0.
, , . () , InheritedPropertySheets Configuration .vcproj.