The old element toasted. Burned-up completely.

I shut the breaker off at the main power box.
In the oven, I loosened two screws to remove the old element (parts now, after the burn-out). I pulled the old element out of the back wall of the oven to expose the wire connections. I detached the simple sliding wire connectors. Done with removal. I waited for the new element to arrive (one week). Installed easily. Turned on the breaker and baked a few potatoes. Very simple.