Here are steps:

1. 
   1. Turn off printer
   2. open printhead
   3. press and hold feed button
   4. power up the printer while holding the feed button pressed
   5. at LCD will written DL mode - then release feed button
   6. Open GoUpdate (or use FW download tool) and printer will be recognize over USB like Barcode Printer 00000000
   7. Download FW and restart printer
2. Also it is possible access printer after putinhg himn at Force DL mode with GoUpdate
   Printer will be recognised like 00000.
   Then you can download printer FW, config file, LCD FW, LCD image.
3.