You need to do the following:
Attach a video monitor to one of the HDMI ports on the Oppo board in the unit.
Either provide network access to the unit by attaching an ethernet cable to the network jack on the Oppo board
OR
Install a USB WIFI adapter in one of the USB ports on the Oppo board. I used a Ralink RT5370 I picked up for $1.50. Here’s the same thing on Amazon.
Either of these options will allow the Oppo app to communicate with the board in the DMP. You’ll need the video at least long enough to setup the network connection for the Oppo. You can then disconnect the video and navigate using the app alone (almost doable) or leave the video connected and use the monitor to navigate discs like you would on any other universal player.
Alternatively, you can add a USB-powered IR repeater to the inside of the case and use a standard Oppo handpiece to control the unit. Any handpiece from a BDP-83 onward should work. This doesn’t require a network connection, but won’t give you the ability to see track lists like you can on the app.
Obviously, this will involve opening the case to access the ports on the Oppo board. If you use a network cable or elect to leave the video attached, you can simply drape the cables out the back of the unit. I CNC’d new openings in the back plate of the case and installed a new HDMI port and ethernet jack. There is a more detailed discussion here.