Take the gears out one by one - I cleaned the grease off as I went as I will be regreasing them with fresh grease when I put it back together.

Once you're down to the last piece with the two spokes, see if you can spin the shredder blade. If it spins freely, then luck is on your side and you can probably skip removing the shredder blade.

Luck was not on my side. It is solidly stuck in place.