I’m always forgetting the commands so here’s the short easy version

From the Terminal menu

system/check-installation
#hopefully it says “status: installation is ok”

#if you’re upgrading from 6 to 7 it needs to know that.. If not skip the below line.
system package update set channel=upgrade

#check for updates
system package update check-for-updates

#get the update
system package update download

#reboot
system reboot

#that’s it.