replace utility sink drain

I received a free Fiberglass Utilitub brand dual basin utility sink (model 26 I believe) from a friend who was remodeling his basement. The end of the drain broke off and he just replaced it. I am looking to replace the drain and use this in place of my single basin one. However, I cann;t figure out how to remove the drain from it to replace it. I tried pliers in the cross hairs of one side, but all that did was break the cross hairs. :furious:

I have read that there is a thing called a drain key that will work, but costs a bit of money. I was also considering just cutting the center out of the drains and trying to loosen them from the bottom.

Does anyone have a suggestion on how to get it out and what to replace it with? Trying to keep this inexpensive.