Unless the shaft steps down in diameter, I can't imagine why a new seal couldn't be pushed in with the shaft in place. I would lubricate the shaft with gear oil and be very careful not to damage the lip of the seal when initially pushing the seal onto the shaft. When replacing motorcycle fork...
It's rotated ~120 degrees counterclockwise (looking from the front), too, right?
I think it's part 36111B in this diagram:
https://www.megazip.net/zapchasti-dlya-avtomobilej/toyota/land-cruiser-38286/fzj80-55818/fzj80l-gnpeka-917290/transfer-case-extension-housing-17815602
That points to both...