The power button would push in, but nothing happened.
Unplugged the unit from the wall.
To access the power switch from the inside, I took the top two screws off the back panel. (Star screws) The top panel then comes off- with a little lift forward from the back.
I had to take off the top two switches to get to this third one, below. They just pulled out- I used a pair of locking pliers, b/c it was hard to get a grip on it.
Then swapped the slip-on wire connectors to the new switch. Mine had brown wires on the two top connectors and blue on the two bottom connectors.
Pushed the new switch in the slot- had to push the on button back on from the outside. Same for the next two buttons. Replaced the top and the two screws in the back.
Really simple!