Having difficulty in understanding the DLL linking to UE4 tutorial

Can some one please guide me on how to use dll in UE4? I know how to create a Win32 dll console app in VS 2013. I’m having difficulty in following the instructions giving the DLL linking tutorial (A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums). I did not undestand the part after “Bind DLL to a blueprint function”!

Can someone please guide me through the necessary steps. I don’t know where should I declare the header file and source file (as described in the tutorial) after choosing file-> add code to project…
Thank you so much!

I eventually figured it out.Let me know if you need help