Excellent tutorial, Kirill! One suggestion: where you talk about removing the main button switches, a photo of the bottom of the board, showing where the switch contacts are soldered, would be even more helpful. Thanks for your very clear instructions and sharing your experience!
Some alternate heat sources for heat-shrink tubing:
* Soldering iron. Hold the iron close to, but not touching the wrap. You may have to apply heat to multiple sides of the wrap, as the convection may not evenly reach all sides of the wrap.
* Cigarette lighter or candle flame. Not a great solution, but works if no better sources are available. If you let the flame touch the wrap, you can end up with soot depsoited on it. Soot will wipe off easily, but it is easy to burn the wrap and wire, even setting the insulation on fire, if you are careless and let the flame sit too long in one spot or for too long.
In the section, Device will not connect to WiFI, the instructions say, “Try re-entering the username/password or making sure to select the correct WiFi network.” How? There is no place to do this.