using the debugger isn't really all that easy.
Just to start from the beginning have you set up the symbol library for it? Use the Microsoft Symbol Server to obtain debug symbol files
It would probably be easier to just upload a couple of dumps here and let someone with it all set up already do it. As you'll also need to know several of the console commands in the debugger to actually get any useful information out of it.
Also, make sure you are opening a crash dump, and not opening an application with the debugger.