References:
Install
sudo pacman -S --needed reflector
Get help
man reflector
reflector --help
Backup mirrorlist
cd /etc/pacman.d
sudo cp mirrorlist mirrorlist.backup
Sort the five most recently synchronized mirrors by download speed and overwrite the local mirrorlist:
sudo reflector --latest 5 --protocol https --sort rate --save /etc/pacman.d/mirrorlist
Check results
cat /etc/mirrorlist