In this video at 16 min. 50 seconds which was made for earlier and he uses boolean effect to carve out a cylinder out of a anvil.
Because of that, there are faces with more than 4 vertices. He uses various methods to reduced faces with more than 4 vertices to 4 vertices.
The problem is that I cannot do what he suggests in the video. I cannot reduce those face because those faces are created by boolean effect, and I cannot do anything with those edges. They cannot be selected.
Do you know any solution for that? In the video, he can edit them but I cannot.
Because you choose "apply" with boolean effect, and that makes carving out effect real but there is no apply button in the latest version of Blender.