Take a snapshot using your digital ocean account, switch it off in your dashboard, then snapshot. Alternatively, all plugins can be removed, even if it breaks your site. The snapshot is only valid on that droplet, so if you destroy it your snapshot goes with it.
Thanks for your response!
So I would start writing the stuff... but I'm afraid it would be then limited to the functions that I'm using for my site, and of course some explanations depend on the theme that I'm using 😄