Flashing process for 55U8N / 55U8K firmware older than build 55U8K_55U8N_55E85GUA_P0414.zip

1.) Extract zips internal .pkg to a FAT32 USB (any size works as long as it is FAT32, does not have to be 4GB like Hisense says, I used a cheapo Verbatim 32GB flash drive). 

2.) Rename the .pkg file on the USB to "forcedupgrade_1.pkg" being sure to not duplicate the extension or include the quote marks. This step may not be neccesary for some flashes but it allows firmware downgrades, so easier just to do it.

3.) Don't plug in the USB just yet. Unplug your TV from the electrical outlet.

4.) Insert the USB to the top blue USB port above the HDMI ports.  Yes it has to be that one.  Yes, with the TV offline.

5.) Grab your remote.  You'll need to use it very quickly in the next steps, so maybe read them first before executing them.

6.) As fast as possible, plug in the TV and immediately point the remote at the TV and press and hold the power button.  Continue to press and hold it until you see the USB upgrade screen.  Then release and wait for the upgrade (or downgrade heh) to complete.

7.) Profit?!?!  If this fails, just remove the USB and repeat the steps from step 3.  You have to get the timing right.  Multiple tries hurt nothing, so keep at it.