How do you ungroup or expand a pie chart in Adobe Illustrator CS6?

If anyone is still having this issue, the correct solution is to ungroup the pie chart. This will convert it from a "graph object" to a standard vector graphic. I saw a lot of responses below with other information that wasn't helpful so I thought I'd chime in. 

Ungrouping does the trick these days, you'll get an 'are you sure'-type pop-up.

Copy chart to ID and then copy back to AI

Object > Flatten transparancy

Right, it stopped working recently.

choose each shape of the pie with the Direct selection tool (A), cut and paste (in place, in front, in back - whatever you need).

One of the pie pieces might still stay as a graph (you wont be able to manipulate it with the other pieces, like rotating together etc.).
What I did was chosing one point (out of 3) in this shape, copying and pasting it (which results in basically the same shape just with one not joined link) and then joining the shape (comand+J). then its all "free'. MAAAAN.

That's the only normal way i found.

MASTEEEER!!

Click on the graph > object > Ungroup > message pops up but click "OK" > then click on the graph again > once the graph is selected right click > select ungroup.

If the little spread sheet thing is open running then it doesn't seem to work. Just closing that window will allow you to Ungroup the object.

I have the same problem too just now, and found the solution was quite simple. It's not Expand menu that works, but simply Ungroup (Ctrl+Shift+G). There will be a warning that once you ungroup them, you are unable to edit the data. So make sure duplicate the original chart first before ungroup them.