Hi friends,I am a beginner in Autocad 3D design, I use Autocad 2D for many years. I tried to make a cylindrical opening on the side, I made a cylinder, put it in my bell and used the "intersect" command. I got an empty cylinder in cross area but it remained solid out of the bell. I do not know how to delete those solid parts. I hope it will be easier if you see the attached photo.Thank you in advance for your help.  

To create the hole in the ring I would use the SUBTRACT command as one option.

Thank you very much