Take lots and lots of pictures with your phone. I did this and it helped tremendously when the time came to re-assemble the disk. Good Luch.
You will need to drop the entire disk gang assembly (axle, spacers, pans, bearings, hanger )
You will need to take the large nut off the end (may need to build a special wrench if you cant find one that fits. May need to use heat, will probably need to use a cheater bar. I actually purchased some specialty wrenches from my dealer (JD) that were about 6' long. You may want to try to get the axle nut loose before you drop the gang assembly.
I refurbished 2 disks so far. One had round axles and one had square axles. Start sliding the components off one at a time and keep up with what order they go back on. They should all be held together by the pressure of the tightened nut. When you put it all back together, you need to REALLY tighten this nut. Not sure you can get it too tight. Run the disk a while, and try to tigheten it some more.