how to change gasoline gauge
 

I have a 96 nissan sentra gxe and when I put gas I notice that the gasoline gauge on the dashboard the arm goes up and down and than it goes back to marking how much gas I have in the tank I want to know where is it location so I can replace it with a new one so it can mark the gasoline in the tank propertly. I have a mechanic manuel but it doesn't show where it is located can some one please tell me I will be very thankful.

why won't you allow the mechanic to it and watch him doing the stuff... ;)