I didn't have a 4.5" holesaw so I elected to use the flycutter. I think next time rather than use a flycutter I will spread peanut butter on the general area and lure a rabid beaver into the hangar to chew through it. I hate fly cutters.
Gave up on the fly cutter and resorted to the nibbler, dremel, and files.
I didn't have any peanut butter and I don't know if they have beavers in Illinois. It came out OK, still have to clean up the rectangular holes some.
If you look closely you can see the reflection of brake-a-saurus in the background.