I can see that there are some holes in the existing flange (presumably what's holding the flange to the floor), but the tops of the bolts have been cut off, so I guess I would need to get an extractor to remove those existing bolts and insert new ones to hold down the extender and existing flange.
I'm hoping to not have to do that.
Can I just use silicone to attach the extender?
Or can I just use the extra thick wax ring?
Which is preferred?