Bathtub Plug Linkage Broken?

I have a bathtub with a concealed plug that's activated from the overflow cover. The linkage broke at the small hook where it attaches to the plug.

My question is how do I remove the plug (which is in the closed position) from the drain so I can replace the linkage? In the alternative, is there any way I can move the plug out of the way so the drain will run? This tub is NEVER used for baths.

Thanks for your help.

Bill from Cincinnati, OH