fuel pump changed running smoothly the gas light is on but I got 3/4 of a tank?

I'm curious, don't you think you should take it back where you had it installed. Now if you installed it, I'd take Pat's advice & just cut the wire.

The electric fuel pump, fuel gauge and low fuel warning light are all in the top of the fuel pump on the one electrical connector. When the "low fuel" sensor sees low fuel level it grounds the wire going to the warning light on the dash. If the light is on with 3/4 of a tank of gas in the car this wire must be shorted or more likely the senor is damaged. Go back to the wire at the tank, disconnect the connector at the tank if the light goes off the problem is in the sensor. If you decide you just want the light out, I can look at a wiring diagram and tell you which wire to disconnect at the tank sender unit.