Check the current minimum requirements page first to make sure that your web host has the required versions of PHP and MySQL.
Check Permissions
Anonymous user needs "read/write" permissions to the entire site. Log into http://www.siteutil.com and select the 'folder permissions' feature. nb: remember to reset the anonymous user to "read" after the update/upgrade is complete.
Take a Backup
The next thing to do is to take a backup of your database. All your posts and pages are held in the database, so you will need to have a copy of it in case, for whatever reason, you change your mind after upgrading and need to go back.
To backup your database, log into the siteutil panel, (http://www.siteutil.com), select the 'mysql databases' option. click on the 'database' link. click on the 'mysql database manager' button. This will open up the phpMyAdmin database manager. Enter the username/password combination for accessing your database.
Once logged in perform the following steps.
- Begin by clicking database in your phpMyAdmin panel. (It may not be necessary to do this, depending on your version of PhpMyAdmin).
- Select the database that holds your WordPress data, the database you created when you installed WordPress.
- Click 'Export'.
- Select all the tables, and check the SQL radio button.
- Check the 'Add Drop Table' box.
- Check the 'Add If Not Exists' box.
- check the 'Save as file' box.
- Check 'None' for compression. If your database is very large, use a compression method.
- Click 'go'. You will be prompted to either open the file or 'save as' which will allow you to select a folder on your local computer. The data will now be saved onto your computer.
Disable Plugins
The final preparation step is to disable plugins. Now, you don't have to do this, but every now and again a plugin hasn't been updated to work with the latest version of WordPress, and cuases a problem after the upgrade. So, it's best to try and avoid that. You can easily disable your plugins by heading to the Manage Plugins page in the dashboard, changing the 'Bulk Actions' pull down menu to 'Deactivate' and clicking 'Apply'.
Ready to Update
Now that you've checked that you're ready to update, you've turned off your plugins, and you've got your backup, it's time to begin your update.