First of all...Thank you very much for choosing FixYa for your technical supports needs.
Here is a link to an online electronic copy of the OWNER'S GUIDE for your machine:http://manuals.frigidaire.com/prodinfo_pdf/Webster/134670300een.pdf
And here is a link to the INSTALLATION GUIDE which may also be helpful to you:http://manuals.frigidaire.com/prodinfo_pdf/Webster/134771500ef.pdf
And here is a link to the actual OPERATING INSTRUCTIONS for that machine:http://manuals.frigidaire.com/prodinfo_pdf/Webster/1319276ef.pdf
To view the Owner's Guide or Operating Instructions just use your mouse to click on the corresponding links, which are the underlined and blue highlighted text just above. This will open a new web browser page automatically for you and allow you to view the information at the website indicated and the contents of the Owner's Manual.
You may need ADOBE READER installed on your computer to read PDF documents.
You can download this free at WWW.ADOBE.COM
Click on the DOWNLOAD ADOBE READER button on right side of the ADOBE home page when you get there, then follow the onscreen instructions to install the software on your computer.
Now, in order to remove the agitator you should first of all unplug the power cord to the unit as a safety precaution.
Next you will have to carefully pry open and lift off the small plastic cap which is on the very top of the agitator center column. Removing this cap exposes the main hold down bolt located inside the agitator column itself.
Now just use an extended socket wrench to unscrew the single securing bolt and then remove it. After that, the entire agitator should lift straight up and right out.
Here are some links to exploded view parts diagrams and parts list for that model showing how the agitator is secured. See parts 54-57 on the following diagram and parts list:http://www.appliancepartspros.com/partsearch/frame_diagram.aspx?diagram_id=1267937&pkw_=basket&model_id=5157990&NewWindow=1 http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5157990&diagram_id=1267937#d1267937
Please COMMENT back here to this page if you have any details to add, have any questions, have difficulty accessing the links, or just require further general assistance and I will respond as soon as I see it.
I hope that was helpful to you, good luck and take care.