Upgrade
You should inform in advance end users that the platform will be stopped. It can be done through mass mail engine and with a side-wide banner.
Check for upgrade
As root, run:
dnf check-update tuleap\*
Upgrade
You should always read the deployment guide instructions before upgrading.
Run as root:
# Stop service
systemctl stop tuleap nginx httpd
# Upgrade packages
dnf update
# Deploy site configurations, run database migration & co
tuleap-cfg site-deploy
# Restart service
systemctl start tuleap nginx httpd
Enjoy all your new features!