I did my own on a 2320.. It pretty much took most of a Saturday morning, but I was not in a rush and had some problems when refilling the transmission/hydraulics..
BTW IIRC- some manuals say to change the hydraulics at 50 and others say at 200.. I would change it at 50 just to get the metal shavings out of there..
I went back with Amsoil fluid for the refill, but I was told the JD low viscosity Hy-Guard is also synthetic. I have not been able to confirm it is synthetic though.
there is a current post on someone doing their 2520 50 hr service that has some advise in it - you may want to take a look there as well
Brian