Get a can or 2 of red brakleen and hose the area off, I'd also pull the cover/drain the rear, because if gear oil is getting out, brakleen/dirt will get in. Dry with compressed air. Once dry I would get seamsealer and do the best to plug the leaks up, then paint the rear. If applied smoothly you can cover up the seam sealer and not know it was there. The seam sealer is flexible whereas jb weld is not. If you axle tubes move in the slightest the jb weld will do no good.
Mine are leaking the same, I plan on doing the fix above, just not high on the list of to dos.
Also make sure the vent in your axle is completely clean and can do it's job. If any pressure builds up in the rear it will push gear oil out of any where it can.