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.