Today WordPress version 3.0.2 has been released as an important security update.
This tutorial will explain how to upgrade your wordpress installation from version 3.0.1 to 3.0.2. 
To upgrade your wordpress installation from wp 3.0.1 to 3.0.2, follow these steps:
Backup your current WordPress blog
If you already have a recent backup of your wordpress site then you can skip this step.If not, then making a backup is highly recommended.
To backup your wordpress installation follow these steps:
1. Open file manager and zip + download all your files to your computers harddisk. You can also download files via ftp if you don’t have file manager access.
2. Export your mysql database using a mysql database manager (phpmyadmin usually). Save the exported file on your computers hard disk too.
Now we are done with the backup, proceed to the upgrade steps as follows:
Update WordPress 3.0.1 to 3.0.2 automatically
Login to your wordpress admin panel to goto the backend dashboard. On top of the page you will see a notification askin you to upgrade your WordPress to 3.0.2
This will take you to the next page where you will be advised to backup your files and database before attempting to upgrade your wordpress from 3.0.1 to 3.0.2 automatically.
Upgrade WordPress
Important: before upgrading, please backup your database and files.
There is a new version of WordPress available for upgrade
- You can upgrade to version 3.0.2 automatically or download the package and install it manually:
On this screen, make sure you have the backup of your wordpress installation and click Upgrade automatically to start the update process.
Please note, during the update process, the wp dashboard will reload a couple of times in some cases, so don’t panic and let it complete it’s process (usually don’t take long, but still have some patience and dont’t interupt the process).
Once the upgrade is successful, you will see this message:
Upgrade WordPress
Downloading update from https://wordpress.org/wordpress-3.0.2.zip.
Unpacking the update.
Verifying the unpacked files
Installing the latest version
Upgrading database
WordPress upgraded successfully
This means that the automatic update from version 3.0.1 to 3.0.2 for your WordPress was successful.
If there was any error in it, state it below in comments.
Update WordPress 3.0.1 to 3.0.2 manually
If you want to upgrade manually from WordPress version 3.0.1 to 3.0.2 simply follow these steps.
Download the latest 3.0.2 package from the wordpress.org official site.
First thing first again! make sure you made a backup of your files and database before before trying to upgrade from WordPress version 3.0.1 to WordPress 3.0.2.
After making sure that you made the backup (and have it on your harddisk, not on server) there are two ways of upgrading manually. One is to simply upload the zip file to the sever and extract it, it will over write all the files that it needs to. This method is to be used by only those who know what they are using, and whats the directory structure that it will form when it will unzip. If you are not sure, then follow the other method for manual upgrading of WordPress 3.0 version to WordPress version 3.0.2
If you are not sure how will the above method behave to do a manual upgrade of WordPress, simply use a ftp client (like filezilla) and upload the files to the server from the zipped wordpress 3.0.2. When prompted, simply accept to replace all the files. You can chose to do this action for all files in the current cue, so that you dont need to press ok for every file which filezilla or any other ftp client will be replacing.
This will upgrade your WordPress from 3.0.1 to 3.0.2 manually.
Again! if you feel any difficulty or have any issues, do let me know! I will try my best to sort if out for you!