There's a few ways to edit a configuration file such as this one, on a Droplet.

• Log in via ssh and use a text editor right in the shell on the command line on the Droplet

Many of the tutorials in our community refer to using either the nano or vi editor directly on the command line in the terminal on the Droplet, including this one: https://www.digitalocean.com/community/tutorials/how-to-configure-and-maintain-ghost-from-the-command-line#how-to-configure-email-for-ghost

• Edit the text locally, and replace the contents of a file via the same text editors

Another simple way is to use your preferred local editor, and simply copy and paste the text to be changed into your local editor, make your changes, and copy / paste those back in via the nano editor in the ssh shell session on the Droplet. Quick and useful if the edits are likely to be infrequent or one-time.

• Edit locally and replace the file on the Droplet via secure copy

You can also copy a file you've edited and saved locally to your Droplet using scp (you'll need a copy of the file saved locally first of course). This is something you do from the command line on your local computer. This answer explains how: https://www.digitalocean.com/community/questions/how-to-copy-files-from-one-server-to-another-droplet?answer=18752

I use ssh and vim to edit the text. I also edit my project locally using git and pull updates to my server.

I use SFTP (SSH File Transfer Protocol) in the FileZilla FTP Client, using:

For the User: root

For the Host: the ip address of the droplet (i.e. 111.222.333.444)