Whirlpool tub drain

My drain type, has to be pushed down once to stop draining and another time to open the drain. It is 12 years old and now it will not close no matter how many times you push down. How do I repair or replace? My home is on a mono-slab so there is no access from underneath.

Hello Gary,

See the image below if it looks like yours use a sharp edge where I have indicated and turn it counter clock wise, good luck