05 Malibu 3.5 fuel gauge fail

I'm restarting a thread about this problem.
After a fill gas gauge keeps going from full to empty for a while and then functions normally.
In posts people have stated that they had to replace the sending unit to fix this issue.
One person has stated that he was able to fix it by tinkering with the level sensor.
Is the level sensor ($50) a part of sending unit ($150)?
If it is can I just replace the level sensor or do I still have replace the whole sending unit?
And what about fixing the level sensor? Is it hard? Do I have to drop the tank?

You have to drop the tank to do this. The level sensor should have a float on it with a metal road hooked to the sensor. The sensor is located on the fuel pump and is connected with two wires.

thanks, all evidence suggests that I should avoid doing this job until fuel pump fails

you have read the evidence correctly!

Except that if GM has an active Technical Service Bulletin (TSB) on this, even though the car is 6 years old, there's a chance you'll get a free fix at a Chevy dealer. My '04 Maxx had it done within the first year of its life, so I don't know more about this. Worth checking, I think.....