Yes as previously posted the seal is often packed full of grim and you can some times get a little more life out of it if you gently pull back the outer lip and rinse it out with something like WD-40. You do however run a slight chance of pushing some of that grim into the transmission so do so with caution.
If/when you pull the seal out you need to remember to do a couple things. There are two seals, the first you can see, it’s a lip seal, the second is an o-ring. When you remove the seal you’ll see that where is a wear bushing installed between the output shaft and the lip seal. The o-ring is located between the shaft and the bushing and prevents it from leaking. Have a look at the bushing and you’ll very likely see that it has two grooves warn into it from the lips on the seal. If the grooves are very slight you could likely install a new lip seal and no oil would leak past. Your best bet however is to remove the bushing and o-ring. Inspect the o-ring (they are normally fine) and if it’s in good condition reinstall it using plenty of grease. If its not obvious be sure to check its location before you remove it so you can ensure its reinstalled in the same location on the shaft. Next you want to reverse the bushing, so the seal’s lips are running on a fresh surface, grease it well inside and out and reinstall it over the shaft/o-ring. I find that it helps if you slide it over the shaft until you just make contact with the o-ring then slightly rotate it so it slips over the o-ring. Just ramming it over the o-ring will likely roll it out of position. Once you’ve got the shaft and o-ring installed grease the seal and install. The next time you replace the seal you’ll likely need to replace the bushing, it will now have 4 wear grooves in it.
Hope that helps,
David