I went to JD parts book page on the 430, and found the pump. Looks similar to the one on the MT I had, only the MT had two halves, not a center section like your 430's.
They're pretty simple to work on. Hardest part will probably be getting the snap ring off the driven shaft, plus the small woodruff key. You'll need to get them off, so as to remove the pump shaft, and remove the old & install the new seal, etc.
I replaced two of the woodruff keys in my MT's pump. One was the, already sheared one in it when I bought the tractor. Apparently someone had jacked up the pressure relief, and I sheared the new one, before I figured out what the problem was.
And you have to keep an eye on the o-rings when you put the sections back together. Watch they don't pop out of the groove, and pinch them, or you'll be buying more.
For some reason, I'm thinking the original body o-ring was square shouldered, but the new had been superseded with a round one. Could be I'm thinking of something else too, as I've had several different one's apart.
And be sure to keep everything clean..!!