The current version of SnowFlat using and embedding only required icons. This is to keep size lower as possible.
So if you want to change any, you might need to work out yourself by adding more icons you required.
I have used fontello but
- You can add additional font awesome fonts by modifying theme layer and adding css files and fonts.
- Or you can add more icons on fontello by make sure you must have to select all icons used in SnowFlat theme otherwise it would be missing.
- Another way is to, select your own list from fontello and use that additional css and fonts file to embed in the theme.
I admit my mistake of not keeping json file with the font files. In fact it was deleted unknowingly
To change icon just follow what Vadym said here
You also can try adding image url to the content property something like below
After long time I am back on the board and dev.. I will start to update SnowFlat soon as possible and will revamp the icons things.. probably add json file included or font awesome..
.qa-nav-main-link:before{
...
content: url('path-to-image-icon');
...
}