3 year old jammed dvd in bluray. How to get the dvd out and restore operation of machine

A DVD should fit without a problem in a blue ray player; but I suspect your use of the word "jammed" indicates something beyond it fitting of not.

Two possibilities: easiest is to find a small unmarked hole somewhere above the tray (assuming it has a tray) where the disc enters the unit. With the power off, insert a long straight pin (opened paper clip works) into the device until you feel a slight resistance. Press just a bit further and you should see the drawer begin to open (don't force it). Once the drawer begins to open, remove the pin and plug the unit in. Hopefully you have now engaged the mechanism that will allow the disc to eject.

If you cannot find the hole, or if this doesn't work, you'll have to remove the cover to get to the mechanism. This is usually a handful of Phillips head screws on the sides and back. If you Panasonic often marks the screws that remove the cover with a small arrow next to the hole to aid in disassembly.