@STHALTJ You'll need 6-8' of 3/8" i.d. rubber hose and a 5 gallon bucket. You'll be using your 32RH's ATF pump to accomplish the flush.
You'll be pumping the old ATF out via the passenger-side port of your transmission cooler at the bottom of the radiator. Depending on your radiator it will have a few different types of output ports and ways of connecting the 3/8" hose you bought to the output port. If it uses a type of port you can't figure out, there's an easy alternative to removing the hose from the port on the radiator.
Cut the hose in half halfway between the radiator fitting and the hard line it ends up at. Buy a 3/8" male-male brass hose splice at your local hardware store like at
https://www.homedepot.com/p/Freeman-3-8-in-x-3-8-in-Male-to-Male-Barbed-Coupler-Z3838MMBC/203518338?cm_mmc=Shopping|G|Base|D25H|25-28_COMPRESSORS_AND_AIR_TOOL|NA|PLA|71700000052227371|58700005026398229|92700043892083304&gclid=CjwKCAjwsIbpBRBNEiwAZF8-z1WVngmVgCE8mJvGrQtUEj0-aGUm92w76xkDbdvvUGUJsrXcuYE1-BoCfxAQAvD_BwE&gclsrc=aw.ds
View attachment 103061
Insert one end of the brass splice into the hose connected to the output port leaving the radiator. Insert the other end of the brass splice into the rubber hose you bought. Now you're ready to do the flush. When you're done with the flush described below you pull the hose you bought off the splice you inserted into the hose leading to the radiator, then insert that end of the brass splice into the other side of the hose you cut that leads back to the transmission. There's not much pressure in the hose and that splice will easily and permanently connect the hose back together. I've had two of those hose splices in my cooling system for going on ten years now.
When ready to pump you'll just shift from Park to Neutral which turns the pump on. As the old ATF is flowing into the bucket, add fresh ATF+4 from the top at the same rate as it's coming out. When the old ATF starts flowing bright clear red, shift back into Park and stop the engine. Reconnect the line to the output port of the radiator, then start the engine, shift to Neutral and add more ATF+4 to bring it to the full mark.
As you're pumping the old ATF out into the bucket, you can stop the flow at any time by just having your helper shift back to Park. That will allow you to catch up adding the fresh ATF+4 if you get behind what has left the transmission.
Make sure it's to the full mark when you're done by checking it with the transmission in Neutral and the engine running.
This procedure is similar for the newer 4-speed 42RLE automatic transmission except you connect the drain hose to the driver's side of the cooler instead of the passenger side as is done for the 32RH transmission. And the engine has to be stopped to stop the flow of ATF since the 42RLE's pump runs in Park too.
You can take the 5-gallon container of the old ATF to any local auto parts store that accepts old engine oil.