Just did this last week. I have an 88 K5 so if yours is like mine -
If you are talking the inner seals, then it is fun to do but a pain. You'll have to remove the diff carrier, the seals install from the inside of the diff housing. I would also do both sides and may as well check the bearings and repack the inner and outer bearings for the hub (you'll need a new seal for the inner ones, the outer ones just fall out) while you're in there.
The inner axle seals themselves aren't so bad to get back in, just have to be careful. I just lightly pressed them in by hand at the diff housing and had a friend tap them in on the opposite side through the axle shaft through the diff housing while I held them in place with a seal press to seat them in place. A few socket extension will make the short side but for the long side I needed a long wooden dowel. Be careful when running the axle back through so that it doesn't tear the new seal, I used a little bit of grease on the end of the axle that goes through the seal so that it would glide in.
Also, there are a ton of you tube videos on how to get your carrier out and I tried all of them. In the end, the only thing that worked for me was a puller and it came right out. Another note of caution, once you remove the carrier bolts, the carrier brackets must go back in the same orientation they came out from what I was told. When you remove them, make sure they don't get flipped around or swapped left to right.
If you don't have one, you need a socket tool for the two spindle nuts. On the go-back, this part was tricky as well, lining up the 'pin' on the inside nut was a pain.
Perfect time to change those MM manual lockers to Warn.
I've never done anything like this before, not even close, so if I can do it, you can too.
