Audio Systems: cd player, lables, cd changer

Question
have 2005 Yukon with cd, nav, am/fm. cd player stuck. has cd's in it won't do anything. can hear the thing clicking like it is changing discs as i drive, but does nothing. screen shows cd 1 track 12 but won't do anything. how do i replace, remove or repair. is is possible a disc is stuck? how do i find out what's wrong?

Answer
yes a cd is stuck or there is some other object inside the radio
we repair this units and 8 out of 10  we find a copy disck with a paper label inside the radio, it gets very hot inside close to 100  this lables peel off the cd and get stuck in the midle of the cd changer tray

sorry radio needs to be service