Okay, I just checked. Both the sender and the sensor have two wires. The sensor is on top, with the wires pointing upwards. The sender is down below, almost directly below the sensor, but just slightly forward of the sensor. Look at the radiator hose, that goes from the engine to the top of the radiator. Look at the place where that radiator hose connects to the engine. The sender is directly underneath that hose. The sender protrudes forward and downward, at about a 45 degree angle.
I'm sure you'll lose some coolant, although I don't recall losing an excessive amount
