IIRC this topic has been covered, but I didn’t find it in searching; so, here’s my question.
I have a representation of a length of PVC pipe drawn. I want to represent drilling holes into them making openings in the side walls. I think the file will show what I mean. The reversed face circles indicate where I want to represent drilled holes.
First position the circle correctly, you have drawn an edge as a guide that appears to be in the wrong place. Remove the edge and soften the other edge.
Then extrude the circle though the wall so it extends out both sides. Select it and Cut to the clipboard, open the pipe group for editing and Paste in Place. (I have context menu Items for these that you won’t have, use the edit menu or keyboard shortcuts.)
Select both parts and use intersect Faces with Selection.
Then delete the parts you don’t want.
As a side note, if you want more than one of these in the same length of pipe, use a short section of pipe for one hole then move copy to make more pipe with holes.