Unplug the washer to ensure it is not getting power while you work on it.
Remove the main housing from the washing machine. The method for this varies depending on what model of Whirlpool you have, but there are usually several screws holding the cabinet in place, as well as clips in the back that need undoing. Pull the housing off after it's disconnected and set it aside. The pump on the washer will be at the front of the washer near the bottom.
Place a towel to help soak up any extraneous water still in the pump. Hook up a shop vacuum to the washer's drain hose and run it to suck out as much water from the pump as possible.
Pull the hoses off the pump as gently as possible, then undo the two retaining clips holding the pump to the motor. Pull the pump off.
Pry the boot off the pump. It should pull off, but you may need to pry it off with a screwdriver.