other icon pack

Hi, I love the module but I wanna change the icons to the Google Now weather icons.
I‘ve already found a website with html and css code, but I‘m kinda new to this stuff and was wondering if anyone could help me where I have to place the code to change the icons.

This is the website: https://blog.avada.io/examples/google-now-weather-icons-semajtwin.html

Thanks in advance,
Domi