Mirror/Copy part from Solid Model

I want to try to mirror or copy this round part to the other side of my cylindrical object, but I can't find a way to do it. I tried copying the front plane and then copying the part, but I was only able to copy the plane. Maybe I should of sketch a circle on both side first. I appreciate any help in sketching something like this faster. By the way how can I copy print screen into a discussion blank space that way I don't have to attach files, thank you.

SolidworksSketching