I just did that job on my gf's 99 250. That particular seal is easy. Its the axle seal on the hub thats a pain. We replaced the axle seal but noticed it didnt even have a dust seal on the axle tube. It hasnt had one in yrs cause the area where the seal goes was all rusty and dirty. Luckily there was no oil comin out the axle tube. So popped in a new seal, and slapped her back together. So far no probs. Since yer there if you have to replace that seal, check yer hub axle seal, the huge one on steroids and the wheel bearings. The outside needle bearing on her truck was bad where the snub shaft pops through. Luckily you can just buy that needle bearing instead of gettn the WHOLE hub unit bearing assembly which is very pricey.