Flashing custom firmware like tasmota or esphome and then restoring back to original

Folks,

I am following this thread closely. Can anyone help to share steps for hardware preperation to install tasmota?

I am aware of general process of flashing and subsequent webui setup but thanks to my poor soldering skills, I am confused on steps to make tinxy device recognizable in flash program.

Thank you.

ON 1N Device you need to hold the push button while powering up the device to put it into flash mode.

Sorry for not making me clear!!. 1N device has been fairly easy to tasmotize.

I would be more interested in understading 2N 4N 6N hardware preperation steps because they involve more complex processes.