John Deere 246 planter help

[HCarver]

Picked up a 246 pretty cheap, in usable condition but I’d like to fix it up some and give it a paint job, it does have a broken fertilizer disk opener and I was able to locate some new disc’s. I haven’t dug into it yet but was hoping someone would know how to remove the disc itself from the fertilizer chute, I’m guessing it has something to do with removing the grease fitting on the center of the hub, thanks