Usually, attempting a publish after changes are made will open a dialog saying changes were made and let you choose which files to update.

Have you published since your changes in VS?

Thank you for responding!

I have published multiple times. In the Customization Project Editor, before I publish, I select Files and the select the Button ‘Detect Modified Files’. It shows the DLL I most recently created from VS, and shows it checked. It also shows my Graph source file, located in the App_RuntimeCode folder, but it is NOT checked. I check it manually before clicking the ‘Detect Modified Files’. But the graph source code is not updated in the Project. As a last resort, I manually copied/pasted the source from VS into the Code Editor in the Project, but there has to be a better way? 

I know the DLL from VS IS being used after Publish, because changes I make are working properly on the WebSite. It’s just the source synching that is not working properly. 

The source is not supposed to be synced after you moved the code to extension library. 

If you moved the code to extension library you only need the dll in the customization package. 

The source code at that point is completely separate and should not be a part of the customization package.

Thank you, Dimitri!