How to unsinstall or delete wordpress blog database and files from your web server.
There are many reasons that you want to uninstall wordpress. Example, if you want to create e-commerce, you would probably choose another e-commerce software although wordpress can be used for e-commerce as well. But we are not going to talk why you want to uninstall wordpress.
There is a few things you should consider before you delete your wordpress blog:
1. Backup database, in case you will change your mind again and want to install wordpress.
2. Backup wp-content, to have copy of your uploaded images, video, etc.
3. How old is your blog? probably you have many posts already and be sure you want to delete entire blog.
4. Deleting wordpress blog might hurt your SERPs for a while, especially when your blogs were indexed by search Engines.
5. If you installed this wordpress with Fantastico, you have to uninstall it through fantastico too. (shown as in following image) 
Once you are sure to delete your wordpress blog, you can do these following steps to uninstall wordpress:
1. Login to your cPanel, and go for “MySQL databases” icon, click this icon.
2. Navigate to “Current Databases” table, and click “Delete Database”.
If you forgot which database you use for this wordpress blog, open “wp-config.php” and look for your database name.
Click “Yes” button once it asked if you are sure to permanently delete your database.
3. For the “Current Users” your database username, you can either delete it or leave it. I personally would leave it, as when i create a new database i would not need to create a new user name.
4. Done with deleting wordpress database, now we go to “file manager” in cPanel Home, and select wordpress files.
If you want to make sure, which files belong to wordpress, you may want to open fresh downloaded wordpress.zip, extract and open the folder and see the lists of wordpress files.
5. Delete all wordpress files from your file manager.
Finally your wordpress blog is gone, and please consider again before you uninstall and delete your wordpress blog as it will be entirely gone, unless you have a database backup.
Video Tutorial:
