Unzip the lcd_panel-engine.zip into a directory.

Unzip lcd_panel-standard.zip into the same directory.

E.g. replace background image in img subdirectory, keep the name same.
Optionally modify screen layout in pages/lcd.xsl,
style for screen items in css/lcd.css/lcd
and way how page is refreshed in lcd/lcd.js.

Run prep.cmd.

custom_web.img file is created, upload this file over already updated firmware
every time fimware is updated.

Dusan Ferbas, 14.9.2021, modified from 10.12.2020 version