Found the manual online.
The receiver unit (the DVD player - not the subwoofer) does have one optical digital input. You can get a standalone Blu-ray player that has an optical output and connect the optical (audio) from the Blu-ray player to the surround system, and the HDMI (video) from the Blu-ray player directly to the TV.
You leave the speakers connected to the surround system as they are now.
On the surround system, you change the input to "DBS" in order to hear the audio from the connected device.
You will have to read the manual for your Blu-ray player carefully to make sure it is properly configured to output audio in a form that your surround system can process (i.e. your surround system may not be able to handle DTS audio from external devices, etc.).
All of this being said, you really should replace this system. Clearly, you've already outgrown it, and using the digital optical connection from your Blu-ray does not allow you to truly benefit from the improved audio formats that Blu-ray has to offer (lossless audio). You can get much better systems for $3-400 if your budget allows.Go to the full post