1978 Rear end Oil Seal Problem

[MLGower]

I have a '78 silver anniverary and I am in need of replacing an oil seal on the output shaft on the Differental. Am I going to need to take out the diff to get inside of it, or is the pinion shaft coupler a press fit? I know that on the input shaft, I can remove the coupler without opening the diff, as it has a nut holding it in place, but this is not the case on the output shafts. Any Advice would be appreciated.

Thanks!!!

Michael