Need help replacing 17" Intel iMac motherboard battery

I am trying to replace the motherboard battery on my 17" intel imac (white enclosure).

The battery is a CR2032 Wafer-type battery.

After popping the case apart, I notice the battery is surrounded by a black ring like enclosure with what look like tabs on one end. I tried to pry the tabs apart to get the battery out with no luck. Then the entire battery and enclosure popped off the motherboard.

F**K

Now I have the battery and enclosure in my hands and still can not figure out how to get the battery out of the enclosure. It is completely encased and looks like it would be sold by Apple or an OEM and one complete unit.

Worse is that it is now off the motherboard and I need to locate some dielectric paste to reattach it.

Any ideas??