bungie
This is done at your own risk.
Get a 4″ grinder, put a metal cutting blade on it. Cut from the centre of the waste to the outer edge VERY carefully, give yourself about 8 – 10 slits. Then use a screw driver to peel up the parts towards the centre like the petals of a flower.
Understand that if you slip, you have a grinder running at high speed in your hands, it WILL damage the bath.As I said this is entirely at your own risk. In saying that I do it all the time
