Project -> Properties -> Configuration Properties -> Debugging
Switch Debugger to launch to Remote Windows Debugger
Remote Command : Your Maya application location
For example, C:\Program Files\Autodesk\Maya2017\bin\maya.exe
And Attach set to Yes
DEBUG -> Start Debugging
Swith to Remote Windwos Debugger
Or press <F5> to start debugging
Before debugging, you must copy *.mll to the folder that Maya can be find.
But if the plug-in has been loaded by Maya, Can not override it.
So you have to unload plug-in before copy.
You can join break point (F9), if attach Maya successful, it should be red point.
But if no attached, it will be white point.
Use Step Into <F11> and Step Over <F10> to step debugging
