Inky pretty much gives the directions
.. but, I would add that it makes it so much easier to clean off the wax if you remove the tank from the bowl. Make sure you have gloves, a putty knife is useful for scrapping the old wax, and use that opportunity to clean the floor really well (since there's a hole in the ground LOL) ... then put the wax ring on and replace the toilet. It's time consuming and just a bit smelly (it wasn't nearly as smelly as some people told me it'd be) but it's not rocket science either. Just make sure to tighten your bolts carefully so you don't crack the bowl or the tank.
oh yeah - when you remove the bowl from the floor, it's best to lift it straight up. That way, the water that is still in the bowl will go straight down into the hole instead of .. umm.. everywhere LOL