How to upgrade Wordpress version manually?

Steps :

1) Backup your database. Read Backing Up Your Database for a detailed explanation at http://codex.wordpress.org/Backing_Up_Your_Database
You can find database details at example.com/wordpress/wp-config.php
 

#mysqldump usrname_wp1 > /home/username/public_html/usrname_wp1.sql

2) Backup ALL your WordPress files in your WordPress directory. Don't forget your .htaccess file. You can find more details at http://codex.wordpress.org/WordPress_Backups#Backing_Up_Your_WordPress_Site
 

#cp -a wordpress/ wp_bak

3) Verify the backups you created are there and usable. This is essential.

4) Deactivate ALL your Plugins.
In your Administration panel, under the Plugins choice, deactivate any Plugins. Because of the changes to WordPress, some Plugins may conflict with the upgrade process.
You can access Wordpress using below URL:-
http://example.com/wordpress/wp-admin

5) Ensure first four steps are completed. Do not attempt the upgrade unless you have completed the first four steps.

6) Download and extract the WordPress package from http://wordpress.org/latest.tar.gz
 

[/home/username/public_html/test]# wget http://wordpress.org/latest.tar.gz
[/home/username/public_html/test]#tar -zvxf latest.tar.gz

7) Delete the old WordPress files. More details at http://codex.wordpress.org/Upgrading_WordPress_Extended#Step_7:_Delete_the_old_WordPress_files

Delete the old WordPress files on your site, but DO NOT DELETE
* wp-config.php file;
* wp-content folder; Special Exception: the wp-content/cache and the wp-content/plugins/widgets folders should be deleted.
* wp-images folder;
* wp-includes/languages/ folder--if you are using a language file do not delete that folder;
* .htaccess file--if you have added custom rules to your .htaccess, do not delete it;
* robots.txt file--if your blog lives in the root of your site (ie. the blog is the site) and you have created such a file, do not delete it.

Upload the new files from your computer's hard drive to the appropriate WordPress folder on your site.

NOTE: If you did not delete the wp-content folder, you will need to overwrite some files during the upload.
 

[/home/username/public_html/test/wordpress]#cp -r * /home/username/public_html/wordpress/

9) Run the WordPress upgrade program and follow the instructions on the screen. Run the WordPress upgrade script by accessing wp-admin/upgrade.php in your favorite web browser and follow the instructions presented on your screen.
* If WordPress is installed in the root directory, point your browser to:
http://example.com/wp-admin/upgrade.php
* If WordPress is installed in its own subdirectory called wordpress, for example, point your browser to:
http://example.com/wordpress/wp-admin/upgrade.php

Below steps will be done by the site owner:-
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10) Update Permalinks and .htaccess. Update your Permalink Structure and merge the custom rules, if necessary, into your .htaccess file.
In your Options->Permalinks panel update your Permalink Structure and, if necessary, place the rules in your .htaccess file. Also see , Using Permalinks for details regarding Permalinks and the .htaccess file.

11) Install updated Plugins and Themes from Administration panel

12) Reactivate Plugins. Use your Administration Panel, Plugins, to activate your Plugins.