The bulb is in a socket inside the switch, pop the switch out and pull the white plastic connector, the bulb will come out with it...go to NAPA or dealer and get a spare...also do a continuity check on the seat heater pad...if the pad has a broken element then it needs replacing...if there is a broken element then the circuit won't happen thus no heat...the drivers and passengers should be separately controlled so that's why the drivers side works and passenger side doesn't...