Seems I have read in the past to put the return line in a catch jug, which you mentioned Junkman. I also read to just pour the Power Steering fluid into the reservoir, have your lovely assistant run the engine and turn the wheels back and forth as the fluid returns to the jug.
Did I read it correctly, you remove the high pressure side and put it into the supply container?
There is also a Filter in the Steering reservoir to be replaced. I would suck out the old fluid, replace the filter and start pouring in the new fluid as the engine is running.
Maybe I read you wrong? .......and iam only starting my second cup of coffee this morning
Then there is the argument that ATF will mess up the seals, to always use PWR Steering fluid
Charlie