Question re. removing CD from case

I received as a Christmas gift a 2-CDs-in-one-case pair of CDs, but I am having trouble removing them from the case. The CD on one side of a door like panel (this internal panel holding both CDs) is held in place by a "button" in the centre consisting of four barb-like hooks at 90 degrees to each other and a donut-shaped piece of plastic connected to four radial bars--this latter set of shapes having no apparent (to me) purpose. The bars in this latter shape are at the 12, 3, 6 and 9 o'clock positions. I have tried pressing hard on the centre donut while attempting to remove the CD but it won't come out. Any suggestions on how to remove the CD? Regards, Ian Douglas