So I am wanting to view the referenced libraries but when I try to open a class file I get this page instead. 
And when I click on "Change Attached Source" This is what I have and I am not sure what should be here.

And when I click on "Change Attached Source" This is what I have and I am not sure what should be here.
3
download MCP is you want the vanilla source code
A .jar only contains .class files and not .java files that they were compiled with. So there is no way to view them, unless you actually look for the source code.
Okay thanks for the help.
