The HDMI port is soldered onto the board. If you have soldering/de-soldering skills, you should be able to de-solder the broken HDMI port from the board, and replace it by soldering in a standard, off-the-shelf replacement HDMI port. If you don't have those skills, it would probably be faster and cheaper just to buy a SNES Classic off of ebay.
I got hold of the rubber band, washed it with soap and water, and then let it sit in rubbing alcohol for a few minutes. Then I did my best to make sure it was completely dry.
You want the light to be going directly into the disc tray so you can see the pulleys. Once I could see, getting the rubber band off and then on wasn't hard at all. I hooked it up, the disc tray popped open, and the system booted up Amped 2, so I am the proud owner of a working xbox.