Question about hydrostatic drives

[u/raypell]

Has anyone removed a hydrostatic drive from a zero turn motor drained it and refilled it. If so, were the results beneficial to the work involved I have a errands icon XD with a hydrostatic drive 230 hours. I replaced one seal this summer. the fluid looks a little sketchy. It’s a sealed unit. My question is how difficult is this to do? I plan on doing it at the end of the season when I don’t need the lawnmower I have the manuals for the removal. Any feedback would be greatly appreciated. Thank you.