Locate the sensor off the exhaust header and follow the wire up to the connector.

Some of the pieces on the top-front of the engine are sharp; be careful what you lean on.

Gently work the connector out of the bracket, then disconnect it by pressing the tab inward then pulling out.

Plastic gets brittle over time. Be gentle and go slow. If it's not coming out, take a break and come back a little later. Be patient to avoid damage.