Most of the breakers are common Square D. YOu turn them OFF remove the wire from the Top Tilt them towards you and the re-install is reverse.
The converter is BEHIND the breaker panel that's the power distribution box.
If it will not reset there are two possible issues
1: Bad breaker
2: Short (I actually have one of those but it's not tripping the blasted breaker. Causes other issues but it's not tripping the breaker.. I resolved it on a temp bases but it's gonna be a while before I clear it and restore everything to normal.)