How do I try latest core from github?

[877dev]

Sorry for the basic question, I want to try the latest code to see if it resolves a problem with a Wemos ESP8266 device, as per the "New Issues" guide. Currently using ESP8266 v3.0.2 from board manager within Arduino IDE.

Do I replace files in this folder (Windows 10, Arduino IDE latest):
C:\Users\username\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2

[JAndrassy]

https://github.com/esp8266/Arduino#using-git-version

[877dev]

https://github.com/esp8266/Arduino#using-git-version

Thank you!