1. Figure out which article you need to edit on the front part of your Joomla site.

2. Click "Article Manager" shortcut after logging in your Joomla control panel.

3. Use the search filter to narrow down the article list. Enter the article name, then click "Search."

4. Alternatively, you could narrow down the article list by selecting one of the article categories.

5. Click the article to edit.

6. Make desired changes using the built-in web editor. 

7. Save your changes. After you have made article changes, visit the public side of your website in a separate browser tab to ensure that your article changes are applied correctly.

8. Go Site, then "Control Panel" to go back to Joomla 2.5 Control Panel.