How do I remove the cd changer for Nissan Frontier LE?

My cd changer reads 'check cd' but there is nothing wrong with the cd's maybe something is jammed inside but I don't know how to remove it. I thought it was just 'frozen' because we had -40 celsius weather this winter but it is around 0 to -10 celsius and still can't play cd's so there must be something inside (my kids probably put something)