I agree that replacement of the stator support requires removal of the transmission guts (e.g. valve body/pump/chain cover/chain, etc. down to the housing)
http://www.shinseiauto.com/japanese/...fordax4s04.pdf
The turbine shaft (673) is shown on the second page of the PDF file (pg 249). Notice that it goes inside the drive sprocket which drives the chain. There's a c-clip that retains the turbine shaft on the drive sprocket, so I don't think you can reasonably remove the turbine shaft through the stator support (even if the shaft could move through the support in that direction).
Unfortunately you'll need to break it down and much of this assembly was never intended to be performed with the unit in the vehicle, so you'll be severely challenged by leaving it in the vehicle.