Cut around the toilet with a razor blade knife. There isn't any under the toilet, you should be able to remove what is left on the floor after you take the toilet up.
I charge $226 to remove and reset a toilet in the Los Angeles area. This is a standard price, but there are always exceptions for vintage toilets and other non common situations.
if it is a PVC flange glued on to the outside of 3" PVC pipe, there is a tool available that will cut it off and you can glue a new flange on the undamaged pipe. It's called a Flange-off. Available...