sorry for my bad explanation - i’m trying to do as “Box” describes here: Countersinking an existing hole, or subdivide the hole ,any videos ..sorry still learning
“How you do it depends on the hole, it best to show us an image to get a more correct answer.
One simple way is to use the scale tool.
First use ctrl+move to copy an edge down the hole then ctrl+scale on the top edge to enlarge it around it’s own center.”