Installing the theme is very easy.
Step 1: Download the theme
Download the latest version of Berry theme from project page.
https://drupal.org/project/Berry
You download file will be a compressed .zip or .tar.gz file
Step 2: Extract the files
- Right click the zip folder and select Extract here
- After extracting the zip file you will get a folder named berry
Step 3: Upload the theme folder
Upload this berry folder to sites/all/themes directory.
Step 4: Enable the theme
Go to administer > site building > themes (/admin/appearance). Click the Enable and set default link below the theme.
Perform basic theme settings
After you have enabled the Berry theme, perform few basic settings from admin/appearance/settings/berry or by clicking Settings link.