No symbols are loaded when debugging a plugin

I am trying to build a custom refactoring but I am unable to debug what I have so far. I have:

  -Created a class library and installed the SDK from NuGet.

  -Created a .nuspec file and build a nuget package.

  -Installed the nuget package into a separate instance of VS with resharper installed in that instance.

  -Placed break ppoint on all methods and properties and attached the debugger to the separate instance.

  -Alternatively I started the separate instance directly from the class library.

After performing all of these steps I am unable to debug. I get the message from VS "The breakpoint will not be hit, no symbols have been loaded for this document."

I do not understand what else needs to be done to debug a plugin. As far as I can tell that is all of the steps listed in the documentation.

I am using VS2015 and Resharper 10.0.2