First - Go back to page 1, look for the link for the downloads - S8X2 LE-8.0.1 & LE-8.0.2 & LE-8.2 images. Click on the line below it which will take you to the downloads page. Then select the version 8.2.3 folder and when that page opens look for your builds based on your boxes.
The file you will need to download ends in img.gz. and needs to be burned to an SD Card minimum 8gig, good quality. Note that the .tar images are for updating a build already on the box.
You need to burn the downloaded img.gz to the SD card. Format the SD card first to Fat32 with a program like SDFormatter. To burn the img.gz to an SD card there are lots of tools to do this. I use Win32diskimager, but if you use this tool you will have to extract the img.gz to an .img file with 7zip or Winrar.
After you burn the img.gz to the SD card you need to open the SD card in a file explorer and copy your remote.conf (this enables your remote to be used with the new build) file and the noncompat.zip file to the SD card.
If you have not burned a build to an SD card or installed a build before you need to read up on that. Start here - [HOWTO + FAQ] Install community builds on S905/S905D/S905W/S905X/S912 device
You can look for your remote.conf file here - remote.conf repository, or google it. The other option is to grab it off your box when running Android via ES File Explorer. Look in the etc folder.
You will also need a noncompat.zip file. I have attached one to this note.