Passive seat belt and door ajar light

[MadMarv]

Passive seat belt on drivers side doesn't close when the door is closed. Door ajar light stays on when vehicle is turned on and driven, the bell keeps dinging (driving me crazy). Is this the switch? If so, where is it located and how do you get to it? I probably can replace the switch myself and save some $$$ instead of giving it to the dealer! Thanks for your help! Greatly appreciated.