Programming AVR Arduino with an ESP8266 via seriell

Hi,

I've an ESP8266 connected to another Arduino (Nano 328P or Mega2560). I just use the AVR Arduino as portextension.

I'm able to load new Code to the ESP8266 via WLAN. Now I want to be able to program the Arduino also via WLAN. My idea is to upload a compiled binary to the ESP8266 and send it via serial to the Arduino.
I think my Laptop is doing the same. Just send a binary via serial to the Arduino.

I've found something in the right way:

But I can't understand it cause of my missing spanisch knowledge and to low programing skills.

Is there anyone how have done this and can give me an example? Or any tips where I can found some hints?

Best Regards
Manuel

Another option might be this. I have tested it and it does work but the caveat is you must be using Linux (maybe Apple Mac) as Windows version of avrdude does not support programming over network.