Check Engine Light - P0461

Any translation from code to English? AutoZone dude told my wife it's a "Fuel cell sensor"

Must be using a different term for something because I know a Mazda 626 doesn't have what most people call a Fuel Cell.

Well it's the Fuel Level Sending Unit that is generating the error code. This looks relatively easy to change if the fuel tank is off.

Anybody here know how easy/difficult it is to drop the tank?