Whirlpool top load washer
On most top load whirpool washers (not including the calypso or the cabrillo) there are 2 main styles for getting the agitator off.
The first and easiet are for the older styles. This will be easy to identify as there is a green ring around the fabric softner dispenser holding it on. Raise the ring up and the dispenser will come off. Underneath you will see a plastic cap. Pry this off with a small flat hear screw driver. Underneath there, there will be a 7/16" bolt. Take it off with a rachet and lift the agitator from the bottom and out of the way.
The second and slightly more complicated method is for the new style. This can be identified by the 4 evenly spaced slots just underneath the fabric softner dispenser. First gently rock the top of the fabric softner side to side. the white top should come off as well as a clear plastic cup underneath. You will be left with 4 white plastic shafts sticking up just above thse slots mentioned earlier. Taking care not to break these shafts, rotate the remaining top piece of the agitator counter clock wise. Once it rotates, pull/ pry it off. Underneath there will be a clear plastic cap with 2 tabs on it. Pull the cap off by these tabs. Remove the remaining 7/16 bolt underneath and lift the agitator off by the bottom.
There are many variations of agitators, but one of these 2 methods (or even a mixture) should get you taken care of. One other thing to mention. Once you take either of the perviously mentioned styles off, you may find a white square hole under neath the dispensers. With this style, you use a 1/2" rachet to unscrew it counter clockwise and the 7/16 bolt is underneath.
If this doesn't seem to match what you have, get me the model number (just underneath the lid to the center rear) and I can get you some step by step directions just for your model.