Hello, So you're saying there is a still a CD manually jammed in between the changer cartridge and the slot that the cartridge fits into? If so, you are going to have to be invasive if you're looking to repair this yourself.
First, unplug the Bose from power, press and hold the Eject button for 10 seconds and release then wait a minute.
Then while pressing and holding the Eject button, plug the system back into power and continue to hold Eject for 10 seconds or until the cartridge ejects (as much as it's going to).
If it does not come out all of the way then your options on a DIY level are to either grab the cartridge and attempt to pull it out forcefully to remove it, or to disassemble the Bose to attempt to retrieve the stuck disc, thus freeing up the cartridge.
If you choose to go that route, let me know and I will see if there's a disassembly manual for this.
Alternatively, if this is not something you're comfortable with then I would suggest sending it into Bose for repairs as they are the only ones that fix their systems and it would be best to have it in their hands in case something goes wrong. In this case I would suggest contacting Bose using the number below:
For assistance with your product, please call us toll-free at 1-***-***-****. For help with our aviation headsets, call 1-***-***-****.
For the best possible service, please have your product nearby when you call. Hours of operation: Monday – Friday: 8:30 AM – 8 PM ET
Other than that, I'm sorry for the bad news here and wish there were a quick fix.