Like Chuck says.
Take the rifle out of the stock.
Remove the ejector.
You will be able to see the end of the shaft from the inside of the bolt rail where the ejector was.
Push out the shaft enough to be able to grab it and extract it.

Another alternative would be to clean the end of the shaft to remove any oil and grease and then glue a metal pin, screw, nail, whatever to it using "crazy glue".
Cyanoacrylate - Wikipedia, the free encyclopedia
Then pull it out using the glued on item as a extension.

D.