It’s so much easy,
- Go to your site via ftp manager (like filezilla)
- upload and replace your logo in theme folder for example look here:
The Favicon is located in your theme directory.
- Joomla: /templates/TEMPLATE_NAME/favicon.ico
- WordPress: /wp-content/themes/corporative/favicon.ico
To change the favicon, simply replace that file.
IPHONE/IPOD TOUCH ICON
The iPhone/iPod touch icon is located in your theme directory.
- Joomla: /templates/TEMPLATE_NAME/apple_touch_icon.png
- WordPress: /wp-content/themes/corporative/apple_touch_icon.png
To change the icon, simply replace that file.