Case 1845C Planetary Drive Service

I have an early Case 1845C with the planetary drives. I want to change the gear oil in each drive. How in the heck does one get to the bottom drain plug on the planetary?? There is an access hole "near" each drive through the bottom chassis plate but it is nowhere situated correctly to remove the drain plugs. Since the chassis plate is a welded structure there is no unbolting/removing the darn thing.



Any tips or tricks for this service? The manual just says remove, drain, flush and refill with 80/90W gear oil. Yeah right. TIA



SimS