Before starting make a backup, update your OS, reboot

Then download migration tool

# cd /tmp/
# git clone https://github.com/rocky-linux/rocky-tools.git

Start the migration

# cd /tmp/rocky-tools/migrate2rocky
# chmod -v +x migrate2rocky.sh
# ./migrate2rocky.sh -r
# systemctl reboot

Postcheck

# cat /etc/rockylinux-release
# cat /etc/centos-release
# hostnamectl