I was referring to the removal of...
If the agitator is stuck, and you have it connected, the first thing I would try is filling the machine all the way up with HOT water and operating, if possible. The heat and steam will help to loosen parts.
Wrap a towel around the top of the agitator and strike gently, if it still has not broken loose.
Using a hair drier, aimed at the top of the agitator will also help to warm.
You should be able to put drops of L.W. into the top of the agitator, after romoving the rubber cover. That will need time to soak into the metal.
Worse case scenario, you may need to ruin the agitator, and deal with the remaining spline. Here is where is may be necessary to drill small holes.