This should help…
https://osmc.tv/wiki/general/accessing-the-command-line/
Or the quick answer if your using a modern version of Windows, hit the start button, type “cmd” and hit enter. At the command prompt type in “ssh osmc@<ip address>” and then enter “osmc” when it prompts you for the password. In Kodi system info settings screen you will find the IP address.
Once connected to the terminal on your OSMC device you can use the following command to update…
sudo apt-get update && sudo apt-get dist-upgrade