How can I remove the agitator?
As recommended by the washer guru Richappy put a rope under the agitator, and pry it off with a 2x4 and the top as a lever.
Here are the break down diagrams for the GE washer http://www.appliancepartspros.com/partsearch/model.aspx?diagram_id=548289&&model_id=229796
Gene.