How Do I Remove The Agitator From My Top Loading Washing Machine?

If it's Whirlpool built that bolt in the center comes out.  7/16 socket with extension. Turn left for it is right handed threads. Someone may have to hold the agitator while you use both hands on the ratchet.

There are no screws that you can see is what you should say. I just removed my agitator and this is how I did it. First light pull up and down on your agitator. Does it move freely up and down a few millimeters? If it does you have a setscrew and you can continue reading.Remove the softener dispenser section off the top. Give a good yank it should pop right off. Now look down and you'll see a ton of old softener built up on the sides and center of the agitator. You can check for a bolt under the blob on the center of the agitator, but mine had no bolt. Look down at the star pattern that is made up of all the supporting plastic ribs of your agitator. Do you see two plastic supports way down near the bottom of the cavity? They don't conform to the star pattern rather they stick out straight and parallel with each other. In between those two plastic ribs you'll find a small 5/16

If you are using older unit with the turquoise colored agitator there is a screw on the side of the agitator that must be removed before pulling up.
But if there's no screw, simply pull it off, it may be hard to lift off because of detergent buildups.

PS. Beware when it lets loose, it will fly off.