I have a theory that for women, it's really the middle ground that is hardest; small light things are easy enough for anyone, and very heavy things level the playing field also; nobody, man or woman is going to lift something that weighs 500 lbs., so you use pulleys and winches and hydraulics to make life easier. But the middle ground is tough because you might have to lift something 150-200+ pounds which will exclude most women and a number of men, but may still be light enough to not normally demand assistive machinery.

In any case, I've had my challenges with PTO shafts on a Kubota + Land Pride mower. The other comment about greasing the PTO shaft & coupler is probably a good start.

I found the biggest challenge to be holding down the retaining ring(?) while simultaneously rotating and pushing the PTO shaft onto the PTO. I don't know about the layout of your spader, but anything to help take the weight off so you can just worry about the alignment part will probably help.