Copy the YSTheme.nds file from the release.zip archive somewhere on your flashcard's SD.
(Optional) Copy the theme folder from the release.zip archive to the root of your flashcard's SD
Update:
Replace your YSTheme.nds file with the one from the release.zip file.
Usage:
Get some theme, copy them in /theme/(theme number)/ Launch YSTheme Select your theme Press a to install it Done!
Made by me.
Tanks FlameKat53 for the bugfix/Some file of this repo (travis.yml).