When I was trying to do this, I bought an expensive socket and then has to grind the outside to get it in there. It turned out that the only impact wrench I had at the time was electric and it wouldn't do the job. When I had it certified, I had the mechanic replace the seal. He told me that the seal surface had grooves and although he cleaned it up a bit, it still leaked. I bought a speedy sleeve and new seal and he installed them for me. It hasn't leaked a drop in 12000 miles.
