Upgrade one PHP-Fusion version at the time
The one thing you need to know is, that you must always upgrade one version at the time. This means, that you can not skip even a minor upgrade version, you have to upgrade the versions one by one*. This is especially important to know for those, who have missed a couple of upgrades and, for example, have to upgrade their site from version 7.01.00 to version 7.01.04 - because then they'll know, that they have to start upgrading from 7.01.00 to 7.01.01 first, and then from 7.01.01 to 7.01.02, and so on...
*Notice, that in some rare cases, there may be an exception to this rule, where several minor upgrades are gathered into one big upgrade package. Be sure to check, if that's the case with the actual download!
Find the correct upgrade package
For example: If your site is version 7.02.00, and a new 7.02-version is released, you need to download the 'PHP-Fusion 7.02.02.zip' upgrade package.
See downloads links in header for the relevant files.
Important - Backup your site, before you start the upgrade! Make a backup copy of your site: The second upgrade rule you need to know is, that you must always make a backup copy of your site before starting the upgrade itself, so that, if anything unexpected should happen, you can always restore your site, bringing it back to the way it was before the attempt to upgrade it.
(If you've already done this, or, if you already know how to backup your site, you just skip this part and go directly to: "The upgrade itself - step by step")
How to backup your site:1.0
Log in to the site you want to upgrade, and click on 'Admin Panel', in the user_info_panel (*a).
*a - user_info_panel:
1.1 Then click on 'System Admin' (*b).
*b - System Admin:
1.2 And choose the option: 'Database Backup' (*c).
*c - Database Backup:
1.3 In the 'Backup Options' (*d), select the 'Backup Type' (from the drop-down menu) to choose, whether the .sql file should be compressed or not, type in your administrator password and finally: click on the 'Backup' button, to save the .sql/.sql.gz file somewhere on your PC.
*d - Backup Options:
1.4 Open your FTP program, log in, and find the server on which your site's files and folders are located - the root of your site (*e). Highlight all the files and folders, and download and save them somewhere on your PC (in the same folder where you saved the .sql/.sql.gz file)
*e - site root:
The upgrade itself - Step by Step
(Notice, that I've use the PHP-Fusion 7-01-04_update.zip package, as an example for the screenshots, and that future updates will have a slightly different look - because of the different content of files and folders of course!)
Step 1 - Translate the new versions additional/changed locals:
Because new locals are often added or changed (and they are always written in English) in the next improved version of PHP-Fusion, it's very important to do one of two things, before you start the upgrade itself: Either: Make a translation of the new locals additional/changed file(s), into your sites own language, and place the files in the right location, in the correct local folder(s). Or: Change the site language into English during the upgrade process - Go into the site administration (*a), and click on 'Settings' (*f), and choose the option: 'Main' (*g). Change the 'Site locale' to English and click on the 'Save Settings' button.
*f - Settings:
Step 2 - First upload step: You must first upload the upgrade script /files/administration/upgrade.php (*h) to the /administration folder of your site and upload the folder named /files/locale (*i) to the root of your site. Without the locale files, some names may not be added to the database.
*h - upgrade.php file:
*i - locale folder:
Step 3 - upgrading the database tables:
Login to your site as the Super Administrator. Under the System Admin (*b) tab of the Admin Panel, and choose the option: 'Upgrade' (*j) then click the 'Upgrade' button (*k). YOU MUST perform the upgrade first! The upgrade process will complete only when you see the 'Database upgrade complete' (*l) confirmation*.
*Notice, that on major upgrades, you may have to click on the 'Upgrade' button several times, before the confirmation text appears.
*j - Upgrade:
*k - Upgrade button:
*l - Database upgrade complete - confirmed:
Step 4 - Second, and final, upload step:
VERY IMPORTANT: Since this release contains a number of structural changes, some elements of your site will not work properly until you have updated all of your files and folders. YOU MUST upload, and overwrite, ALL of the files and folders, from inside the upgrade packages /files folder (*m), to the root of your site.
*m - Upload all files and folders:
That's all - you site should now be upgraded to the next version of PHP-Fusion - enjoy! Many thanks to Harly for writing this guide