Hi T_Jim,
I agree with all the replies & there's nothing like doing it yourself "the peace of mind" that you get from it.
My approach was to use compress air & blow it out first from the inside & then on the outside. Inspect the screen, if it looks good ,reuse oring (make sure that they are in the grove, use light grease to hold them there), tighten & inspect for oil leaks, after you refill UDT fluid.
Strange thing up here in Canada about the SUDT, the Super UDT does not exist, cannot get it from Kubota dealer? If there was a place that would require the Super (for extreme temp) it would be here. It looks like the "Super" may stand for something else "money scam". I'm using the Walmart UDT oil, which is has the Kubota UDT approve equal on the label.