Depends on how fast you are with a filter change....
Have everything ready to go and whip the old ones off one at a time and whip on the new ones. Are you sure there isn't a restrictor in the lift gate cylinders? My NH round baler has them to keep the tailgate from closing too fast. Far as I know, unlike the smaller Kubota's there is no strainer, just the high pressure filter and the low pressure filter which interchange (at least on my M's they do).
I have to say I dropped my fluid at 50 hours and changed it out.
You'll loose some so have a drain pan underneath unless you are on gravel. If on gravel, it keeps the dust down.
The first filter change is always a bugger. Kubota OEM from the factory filters are always tight. Be prepared to 'wrench' on the filters. If I remember correctly, I rammed a big screwdriver through mine and levered them off that way but then again, I dropped my fluid anyway.
I suggest using Kubota Filters over anything aftermarket. They really don't cost a lot more and you know they are made to OEM specs.