1. Download new application launcher from site: https://store.kde.org/browse?cat=398&ord=latest
2. Run command:
plasmapkg2 --install LauncherName.tar.gz
If you want to upgrade launcher to new version use command:
plasmapkg2 --upgrade LauncherName.tar.gz
3. Right click on Start Menu icon > Show alternatives > Select LauncherName
If you want to uninstall launcher use command:
plasmapkg2 --remove LauncherName.tar.gz