Add repository in /etc/pacman.conf
i686 or x86_64
[archlinuxfr] Server = http://repo.archlinux.fri/$arch
Sync with all repositories
pacman -Syu
Install yaourt
pacman -S yaourt
How to use yaourt
Basically yaourt is a script, a wrapper of pacman.
System upgrade, check all packages
yaourt -Syu
Install or build the package via PKGBUILD from AUR
yaourt -S
Fully upgrade all AUR packages
pacman -Syu --aur