Jensen RV audio equipment is sold to manufacturers from ASA Electronics.
Here is a link to their website and support contacts:
https://www.asaelectronics.com/
Troubleshooting PDF for your DV352WIN:
https://asasupportdocs.blob.core.win...ng%20Guide.pdf
I looked and they make no mention of how to extract a stuck CD.
Most CD players have a small hole that you can push a unbent paperclip in to manually eject the CD if it get's stuck. Looking at your photo I don't see one of those on the lower CD part of your system. I do see a similar small hole or indent on the upper unit on the lower right hand side.
It's possible that that is something to help, but I also think it looks like a place to do a factory reset of the electronics of that upper unit.
I searched for an User Manual, but no luck there.
Here is a phone number to call for support:
(800)688-3135