Official updates will be made available OTA (over the air). The box will notify you of the update and offer to install it. Alternatively, any firmware update can be downloaded to USB stick and installed through system menus. Settings - About - Update.
To downgrade firmware first do a full / emergency firmware reflash (see link at bottom of firmware section for each model) then update to desired firmware.
This thread only lists key updates, there are many intermediate beta firmwares available on Zidoo's forum.
Zidoo UHD3000 / NEO ALPHA / NEO S / NEO X
- 6.4.42 (UHD3000) / 6.7.42 (NEO ALPHA / NEO S / NEO X). 18-OCT-2022: http://forum.zidoo.tv/index.php?threads/beta-version-v6-4-7-42-for-z9x-z10-pro-z1000-pro-uhd3000-neo-s-neo-x-neo-alpha-release.94619/
- 6.4.20 (UHD3000) / 6.7.20 (NEO ALPHA / NEO S / NEO X). 28-JUL-2022: http://forum.zidoo.tv/index.php?threads/beta-version-v6-4-7-20-for-z9x-z10-pro-z1000-pro-uhd3000-neo-x-neo-s-neo-alpha.94137/
- 6.4.06. 21-MAY-2022: http://forum.zidoo.tv/index.php?threads/beta-version-v6-4-06-for-z9x-z10-pro-z1000-pro-uhd3000-neo-s-neo-x-release.93680/
- 6.3.92. 06-APR-2022: http://forum.zidoo.tv/index.php?threads/beta-version-v6-3-92-for-z9x-z10-pro-z1000-pro-uhd3000-neo-s-neo-x-release.93323/
- 6.3.60. 25-NOV-2021: http://forum.zidoo.tv/index.php?threads/new-version-v6-3-60-for-z9x-z10-pro-z1000-pro-uhd3000-release.92034/
- 6.3.35. 20-AUG-2021: http://forum.zidoo.tv/index.php?threads/beta-version-v6-3-35-for-z9x-z10-pro-z1000-pro-uhd3000-released.90320/
- 6.0.90. 19-JAN-2021: http://forum.zidoo.tv/index.php?threads/beta-version-v6-0-90-for-z9x-z10-pro-z1000-pro-uhd3000.84816/
Emergency FirmwareUse only if anything goes wrong or if downgrading firmware:
https://www.zidoo.tv/Support/support_guide/guide_target/bTvt%2B8mjABzeq7k9e%5Bld%5D3ulg%3D%3D.html
Google Play ServicesBy default Zidoo's firmwares do not include Google Play Services. To use Google Play Services (Play Store) you must install a firmware version with a _G suffix. Guide here: https://docs.google.com/document/d/1ALcOI6vHav3t8PgVUxdE0X8xb1aTrmGZ/edit