How can I change the renaming of project files and class files using Visual Studio?

I finally finished working with my ASP.NET Webapplicaton, and my solution contains three projects: the web application itself, WCF and Classlibrary. But I would like to reorganize it to change class names, project names, etc. How can I do this smoothly so that everything doesn't get messed up like namespaces etc. I also have a Resharper, but I'm new to this.

When I renamed my project file and .csproj etc., I still have problems with namespaces, the new namespace does not work, it asks for the old one.

Thanks in advance!