help me get the Intermediate Language out of an unmanaged C#

I have a C# program, now outdated, but I'm working on a project that's similar to what that program does so I thought I could get the IL out of the exe n dlls and then use reflector to get the code n mainly the functions im interested in. When i try it with my code, works. I tried it with the other exe n dlls, says unmanaged assembly. Where do i head from here now..