First time install:

1. The main theme files are in the "zero-one" folder
2. Copy all files from that folder to your desired folder (locally or server)
3. And it works straight away

Changing demos:

1. Delete the main content folder from your install
2. Add "content" folder from any of the demo folders instead of it
3. Go to site panel, to Site Styling tab, turn on the Style Compiler, and save
4. Go to any frontend website page, and refresh it
5. Wait a for a several seconds and new styles will be generated
6. That's it!

Updating:

1. Every update has its instructions at https://www.one.thezero.club/changelog
2. But in 99% of cases this is what you should do https://www.one.thezero.club/guide/installation/updating