Here's a way to do it with LINQ to XML, complete with sample code:
Quickly Import and Export Excel Data with LINQ to XML
It's a little complex, since you have to import namespaces and so forth, but it does let you avoid any external dependencies.
(Also, of course, it's VB .NET, not C#, but you can always isolate the VB .NET stuff in its own project to use XML Literals, and do everything else in C#.)