How to upgrade phpBB3
In this article we'll show you how to upgrade your phpBB3 forum through the administration panel using an automatic update package.
You can check whether your phpBB3 forum is up to date from the System tab of the administration panel. If there's a newer version you'll see a red banner prompting you to upgrade your application. You can use the link on the System tab page to go to the download section of the official phpBB3 site and download the respective automatic update package (e.g. phpbb-3.0.8_to_3.0.9) to your local computer.
Then you have to unpack the downloaded archive and upload the whole install folder that's inside to the root phpBB3 directory on your hosting account (e.g. public_html/phpBB3). You can do that with an FTP client. After you upload the install folder, you have to open its URL address with your internet browser (e.g. yourdomain.com/phpBB3/install). There is also a link for that on the System tab page of your administration panel.
After you access the URL address, click on the Update tab in the upper-left corner and click on the Proceed to next step button.
On the next page (Version Check) click on the Update database button. On the following page (Perform database update) confirm the action by clicking on Update my database now.
On the next screen you'll see the results of the database update; click on Continue the update process now. Then phpBB3 will check for file differences and on the next page you'll see the new files that will be added to your installation. On the same page you also have to choose the update method by clicking on one of the two buttons at the bottom of the page: FTP upload or Download modified files archive. In our example we'll use the second method (Download modified files archive), which is also the recommended one.
On the next page (Download modified files archive) select the type of archive you prefer (e.g. ZIP) and click on the Download button. After that unpack the downloaded archive and use an FTP client (e.g FileZilla) to upload all the files from your local computer to the respective phpBB3 folders on your hosting account. Upload all the files inside each folder but not the folders themselves; otherwise the folders on your account will be replaced and you'll lose files in them that do not need to be updated.
On the same page of the administration panel you'll see the paths for all the files that have to be uploaded. After you're done click on the button Continue update now. If you did everything correctly, you'll receive a confirmation message that the update was successful. The last thing you have to do is to delete the install folder (e.g. public_html/phpBB3/install) from the root phpBB3 directory on your account.
You can also check out the phpBB3 Upgrade Tutorial for more detailed information on how to upgrade your forum.