I did it on my 86 k5. It is very simple. Jack up the truck, and put it on jack stands. Remove tires. Remove the drums. Remove diff cover. Rotate the diff so you can get to the lock pin and the pinon shaft. Take out the lockpin and the pinion shaft. use a small screwdriver to rotate the c-clips and then use a pencil magnet to slide them out. You may have to push the shafts in a little to get to the c-clips. Once the clips are out, the shaft will slide out of the tube. then just use the end of the shaft to pop out the old seal. Then put in your new seals by tapping them in w/ a large socket. And then as they say, assembly is reverse. If the seals are leakin that means u have gear oil in the brakes, which prolly means they are toast. My drums were. Now would be the best time to replace em.