Removing the Blades
Scags are wonderful machines and have been the backbone of my yard company. Unfortunately maintenance is not the easiest thing to manage, especially for the blades. Usually the bolts take a large amount of effort to remove due to how tight they become over use or when they come brand new.
The method that my dad came up with was to take two 15/16 wrenches and apply them to both ends. First remove the two coverings on the right and left side of the deck covering the top of the blades. Take the bottom wrench and make sure that you set wrench against the deck of the mower. Now turn the top wrench to loosen the bolt. Here is the point that will take some elbow grease and it is possible that you may not get it off. Applying oil to the nut at the top can help to move the nut and getting a post driver to to cover the top wrench provides enough leverage to usually remove the nut from the bolt. The mower is not high enough off the ground to take the blades off after the nuts have been removed. Take a jack and raise the Scag high enough to remove the blade.
Use two people if possible to carry out this technique. Four hands are better than two and make sure that the both positions are secure while you or coworker remove the blades. The main advantage is the added strength of both of you to aid each other if necessary. However if you are stuck on your own two wrenches on the top and bottom still work. You just have to ensure the bottom wrench is locked securely in place so it does not fall off when you turn the nut. Hold the bottom wrench in place and slightly turn the top to apply enough pressure that it stays in place the entire time. Once the pressure is applied you will want to start removing the nut from blade ensuring that you maintain pressure the entire time or the wrench will fall off.
Here are a few tips to prevent the extra effort for future blade switches. Apply oil to the nut, clean all the pieces with a wire brush, and tighten only enough to make sure the blade stays on. Another easy method that helped myself is higher quality blades and ensuring you sharpen them correctly. The better a blade the longer they last and the least amount of times it takes to chance them. Likewise if you sharpen the blade right you can give a quality cut without the blade wearing down or shattering. Lastly clean out the deck, a lot of grass clutter can dull the blade, make it harder to cut, and makes removing the blades that much more difficult.
Here is a few pictures of where to apply the wrench:
In the middle of each blade you will see the bolt. Place the 15/16 wrench around each one and turn in the direction where the nut will come off. Repeat technique with each blade and make sure you are turning the wrench so that it loosens and not tightens. Remember "righty tight lefty loosey."
The panel to remove is at the bottom of the picture with the nut in the middle of the box. There are four knobs that tighten to hold the panel down. Loosen all of them to remove the cover and repeat on the other side.
That should cover all the details about blade removal for Scag Zero Turn mowers. Please ask in the comments if you have any questions or additions you recommend. Thank you and please feel free to compliment or criticize as you see fit. Thank you.