As I explained in the other post of yours you need to copy the aip file produced from building your project to the Ilustrator's Plugins folder. You can do this manually or via Post build setting from within Visual Studio. Then you can debug the plugin in two ways.
Launch Illustrator manually and the use the "Attach To Process" option from Visual Studio and attach to the Illustrator.exe process
Set the Command path to the Illustrator.exe path. It can be accessed via Project > Properties > Configuration Properties > Debugging > Command(The path may vary, I am writing this based on some internet search). The run the debugger of Visual Studio, it will launch Illustrator and attach the debugger to it