There are two options this step.
Installing toilet flange on wood floor.
Next install a new wax ring.
But if your floor is severely rotted say more than an inch beyond the flange you re stuck replacing the flooring around the toilet.
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Rest the toilet bowl on its side place it on a towel or cloth to protect the floor and attach the replacement wax ring to the bottom of the bowl this technique helps ensure the ring is in the proper position when placing the toilet over the flange.