What ya have ta do is take your driveshaft off the pinion, mark the nut to the pinion with a scribe so you get close on your preload, make a tool that will hold your flange and hit the nut with a socket and an air impact to take it of after taking the locking dent out of the nut with a small punch, slide the flange off pop the seal out hammer in a new one and reverse the order that you took it appart.p.s. don't forget to line up your scribe mark and reset the lock nut.