I removed mine not too long ago. In addition to replacing the seals, assuming you are referring to replacing the bearing "O" seals, realize you may need to replace the paper thin gasket which sits between the outer hub and axle shaft. I suggest cleaning and prepping the two sides for placement of a new gasket when reassembling.
The only special tool I needed, besides a wrench for a eight sided lock nut is a puller, home made or stock. I was able to use a three legged puller, a bit cumbersome in setting up, but worked for me. Someone showed me a picture here of his homemade version which is very effective. You can view more by searching here if you so desire.
And btw, you should make a note which side has the hub with the reverse threaded lock nut used vs. standard or non-reversed, so you don't end up losing your wheels accidentally. Also, behind each lock nut, is a lock washer which SHOULD have incorporated, a tab along the inside diameter that slips into a holed section of the outer hub (mine were bented away for some unexplained reason). I also remember that the lock nuts are to be on tight when reassembling.
All in all, I feel it was not a very complicated process (well...and with the help I got here).
PS. Added Note: I assume you already have the rear drum and brakes removed by this time.