Specifically what Model and year of Jeep are you working on ?
The process will vary based on your make and model of JEEP, but the fuel sending unit is located inside the gas tank and in most cases replacement requires removal of the gas tank from the Jeep.
In the fuel tank
Remove the gasoline from the gasoline tank. Remove the fuel line from the gasoline tank. Remove the fuel sending unit retaining plate. Reverse the process to install the new fuel sending unit.
you have to remove rear seat ,under the seat there's two covers , one is for the fuel pump , the other is for the fuel gauge sending unit .Remove cover on passenger side and remove fuel gauge sending unit .
Lower the Gas tank. Remove the sending unit/fuel pump from the tank and replace the unit. The sending unit and fuel pump come together.
The only way to gain access to the inside of the fuel tank would be to remove the tank from the vehicle then remove the fuel pump/sending unit assembly from the top of the tank.
Remove the fuel tank and then the sending unit. The fuel pump is on the fuel sending unit bracket.
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Try replacing sending unit
Run the truck until you have less than a 1/4 tank of fuel or siphon the fuel out. Remove the front seat. Remove cardboard cover that covers the fuel tank. Disconnect wires and fuel line to sending unit. Remove the sending unit from tank. Reverse for assembly.
you have to remove the fuel pump it is connected to it, it has to be replace as one unit
You have to remove the fuel tank.
Remove the fuel sending unit from the fuel tank (the process to do this depends on what your vehicle is), unplug it from the weatherpack connector, install the new unit, plug it back in.