I am new to using the Arduino. I have followed the steps on the instructions up to "3. I added the location of the avrdude executable to my path Path= path=C:\MyDev\arduino-1.8.19\hardware\tools\avr\bin;%path%."
I plugged the UNO back in typed in the "arduino -P com4 -b 19200 -c avr isp -p m328p -v."
I got the following message "'avrdude' is not recognized as an internal or external command,
operable program or batch file."
Any way you can upload a video walking through all of the steps?
Here's something that might help you as well: https://hackaday.io/project/19935-install-avr-tools It should automatically set the path for you.
If you open a command prompt, and type AVRDUDE, what do you see? (By looking at your comment, it doesn't look like you used the proper path... but just took the sample one from the document... if that's correct... you need change it to match the actual path to your Arduino IDE's bin directory. Once you know the full path, and if you see the error, you can simply include the full path to the AVRDUDE.EXE file instead of just AVRDUDE. (If there is no error, just type the following command without the path in front of it, or include it... it'll still work.) So, yours might look like this: C:\Program Files\Arduino\arduino-1.8.19\hardware\tools\avr\bin\avrdude -P com8 -b 19200 -c avrisp -p m328p -v -e -U flash:w:SelectorFirmwareMK3.hex:i
Obviously, your path must match the real one... so make sure you change the highlighted and bold part to where the Arduino hardware directory actually is.
As for videos, there are plenty of them on YouTube about this process... just search for "using an Arduino as an ICSP programmer". (https://www.youtube.com/results?search_query=using+an+Arduino+as+an+ICSP+programmer)
Hope that helps!