How to select circle to extrude?

Hi,
  I am new at this so bear with me please.  I make a cylinder in silo, and drag the top lines and SHIFT X to cut. Then that leaves a smaller circle in the top of the cylinder where I can select those and press the Z key and a little ball appears that I can move the selected area in or out. I turned of the quad selection and made a cylinder with NVIL but can't seem to figure out how to do the same. Could someone please explain how that is done with NVIL? 
Thanks,
crestburg

please in pictures I do ,not understand English

There you go. Thanks for looking.
crestburg

describe as easy as possible, I can not understand that it is necessary

something like this?

https://www.youtube.com/watch?v=tRMoM0flmSw&feature=youtu.be

something like this?

https://www.youtube.com/watch?v=tRMoM0flmSw&feature=youtu.be

YES. That is exactly what I wanted to know. Thank you. 
crestburg