nixCraft published a tutorial about upgrading OpenSUSE from 15.1 to 15.2 using the CLI.
How to upgrade OpenSUSE 15.1 to 15.2 using the CLI - nixCraft
A step-by-step guide explains how to upgrade OpenSUSE Linux Leap 15.1 to 15.2 using the command line option.
How to upgrade OpenSUSE 15.1 to 15.2 using the CLI - nixCraft