If you look at
Section 8 of the
Quick Reference spoiler at the top of Post 1, you will a
Repository of Patched Firmware Files. If the firmware for your device is included in that post, simply download it and follow the instructions in this guide for
using a 3.3V USB CH341a programmer.
If the firmware for you device is
not included in that post, then extract the firmware using the 3.3V USB CH341a programmer and post that file here. I can modify it for you, but there are no guarantees it will work. Always keep two backup copies of the original firmware extracted by the CH341a programmer because it might be necessary to flashback the original version at some point.