New Holland 474 Wobble Box Leaking- Seal Replacement

[SkylineAcres16]

The wobble box on my New Holland 474 haybine is leaking and I have to put gear oil in it before every use. It appears it is coming out of the horizontal shaft that the flywheel is attached to. Has anyone ever put a new seal in this area? It looks do-able but I don't want to get in over my head either. I'm trying to figure out if it's something I can tackle. What happens when I take out the 4 bolts at the universal joint/flywheel junction? Should that expose the area I need to be to put the new seal in? Thanks for any information!

 

[SkylineAcres16]

This is supposed to be the exploded parts view of it. #27 is the oil seal. #25 is a shim and #26 is the retainer cap.