I believe MAC tools has the puller to do it. There is a topic with a picture of the puller, which is like a tripod with three places for lug bolts/nuts to be attached to the base and then a bolt and a hammerhead piece that attaches to the end of a bolt that will be tightened against the axle end. You use a sledge hammer to tighten the drum puller, then you use a wheel puller to pull the axle from the housing.
It is a tapered bearing assembly and there are end play specs. That keeps the bearings running practically forever and keeps the seal in proper relationship. You may need to make shims to adjust the end play. Cups are set with the tapered face inward. Add shims to the flat back of the cup to decrease clearance. I would check the end play before I pull the retainer to see if it needs adjustment so that the seal does not get disturbed by the shimming process.