Maschio Gear box change

[lCSresearch]

I am trying to change a the pto shaft on a maschio dl 1500 harrow. Going from a single to a double ended shaft. neither the dealer or the manufacturer has been any help what so ever. as the photo shows the vertical shaft has to be removed from the base to open the gear box and change the pto shaft out. just wondering if anyone has worked on these or know where i could get my hands a tech manual. once again the manufacture and dealer dont have one. there is a nut on the vertical shaft but it will not come loose, i have the lower case gear box design.