Download the manual and study the parts about Setup. It's somewhat complex, especially since you need to use a TV with a Composite video input (the Component Video or S-Video won't display Setup). There are also some undocumented features of the Setup. Nothing too exciting, but take a look on this forum. I posted a few of them.
Remember that the video from your DVD/BluRay player should be connected directly to your TV since the MX-119 has no HDMI inputs. Then, use your TV's input switching to select the DVD/Blu-Ray player. Use the 7.1 RCA outputs from your DVD/BluRay player to connect the DVD/Blu-Ray audio to the 7.1 inputs on the MX-119.
Make sure that during the winter you thoroughly de-static-ize your body before getting anywhere near the MX-119. Static electricity killed my MX-119 and it took me many hours to repair the blown IC circuits on a very inaccessible board inside the MX-119..