How to Install a fuel sensor in the tank

I have an 2005 Envoy SLT and my gas gauge is stuck on empty and the check engine light is on as well. Did just replacing the fuel sensor correct everything? How much did it cost?

Thanks for your help.

dropping the tank is pretty straight forward. Two straps on the tank 2 15mm bolts hold the straps. brace bar under vehicle has to come off. 4 15mm bolts. disconnect the fill hose disconnect two gas lines at front of tank. unplug vent solenoid and two evap vent hoses. the tank should come out.then on top of tank disconnect fuel tank pressure sensor and sending unit connector,and the tank should be out. there is a metal retainer ring holding the unit in. there is a special tool to use to take it off but you can use a hammer and screw driver. after removing the unit you just unplug the level sensor and unsnap the sensor out of the holder. you can test it by using an ohm meter. hook each lead to each side of the level sensor then move the arm from on side to the other. it should measure from 40 ohms to 240 ohms. if the reading is erratic or goes to OL the level sensor is bad. Also, what code was it,is it a p0463? I have changed hundreds of these. It is a very common problem.

I do not know the error code. The shop is charging me $200.00 for the sensor and three hours time. This sounds high considering what you explained.