How to enable new User Experience for SharePoint Online Document Libraries and Lists

Microsoft is rolling out new user experience for Document Libraries and Lists in SharePoint Online. If you are a SharePoint Online tenant user and want to test new User Experience for your Document Library and/or SharePoint Lists then perform following steps:

Document Library:

1. Open Library Settings
2. Click Advanced Settings
3. Scroll to bottom of the page, you will see a new setting called List Experience, similar to following:
5. Click New experience
6. Click OK

SharePoint List:

You can try the same steps for SharePoint Lists also but if they do not work, here is another trick:

1. Navigate to your desired list
2. Append a QueryString parameter TryNewExperience=true in your url and refresh the page
3. Example:
   1. Original List Url: https://yourdomain.sharepoint.com/Lists/Test%20List/AllItems.aspx
   2. After QueryString parameter:  https://yourdomain.sharepoint.com/Lists/Test%20List/AllItems.aspx?TryNewExperience=true