i would do the pressure test beforehand.....
then....
remove the control valve and check the clutch pack

your choice though....
if the clutchs are worn out you'll know it
just go by that which L1ftmech suggested on how to check

as for the fluid there are a couple types that are dextron and/or clear transmission fluid....
i was looking in the manual for this model and there are several breaks in the model and it displays several transmission sections for manual shift clutch type, and 2 other automatic torqueflow type ones.
can you find any tags on the transmission housing and see if you can pull any info off it. That might help determining which one it has and then we can determine what fluid goes in it for sure instead of guessing at it. ;o)