I don't know about access to the connector on the 1200. But the tank doesn't need to be drained to remove it.
The sensor is 22mm across the wrench flats. After the harness is disconnected and fished through the frame, I think use a 22mm combination wrench and a 3 to 4 pound sledge to tap on it. 'Dead' blow hammers are the wrong tool to create a 'live' inertia impact with.
Hammers from Harbor Freight