It makes for a much neater job to pull the toilet. WHen replacing it, you'll need at least a new wax ring, and it's not a bad idea to replace the supply hose (if it's a solid riser, it'll probably be okay, but since you've raised the toilet the thickness of the tile, you may have to either shorten it or (probably) bend it a little). You may need to replace the toilet bolts that hold it down if they were steel and have rusted since they may not come off. Use SS or brass new ones.
Other than being heavy, resetting a toilet isn't really all that hard.