Lower Unit Oil Below Impeller Leaks Oil - 97 Yamaha S150TXRV

[boatmon345]

I have my 97 Yamaha 150 (S150TXRV) lower end off to change the impeller, and while I was at it I changed the lower unit oil. What came out was very black oil. I pumped full of new oil, then just for kicks I turned the entire lower unit upside-down to see if any oil leaked from the input shaft seal below the impeller. Well it did leak a little.

I assume that this is not suppose to leak, right? Does this mean I should replace the oil seal? And if so, is it just a matter of prying the old seal out and the pushing the new seal in?

Thanks for any guidance.