WordPress Theme Editing

When modifying a WordPress theme, you can leave the original untouched and make changes to a backed-up copy of its files (called a child theme).

1. To easily identify the child theme you are using, combine the theme name and create a new folder in « wp-content/themes ». (For example, if the original theme is « twentyfifteen », create a folder named « twentyfifteen-child ».)
2. Copy the original theme’s « style.css » into the child theme folder, then edit « Theme Name » and « Template » as shown below.
   [php]/*
   Theme Name: Twenty Fifteen Child
   Theme URI: https://wordpress.org/themes/twentyfifteen/
   Template: twentyfifteen
   Author: the WordPress team
   Author URI: https://wordpress.org/
   Description: Our 2015 default theme is clean, blog-focused, and designed for clarity. Twenty Fifteen’s simple, straightforward typography is readable on a wide variety of screen sizes, and suitable for multiple languages. We designed it using a mobile-first approach, meaning your content takes center-stage, regardless of whether your visitors arrive by smartphone, tablet, laptop, or desktop computer.
   Version: 1.5
   License: GNU General Public License v2 or later
   License URI: http://www.gnu.org/licenses/gpl-2.0.html
   Tags: black, blue, gray, pink, purple, white, yellow, dark, light, two-columns, left-sidebar, fixed-layout, responsive-layout, accessibility-ready, custom-background, custom-colors, custom-header, custom-menu, editor-style, featured-images, microformats, post-formats, rtl-language-support, sticky-post, threaded-comments, translation-ready
   Text Domain: twentyfifteenTemplate: twntyfifteen
   This theme, like WordPress, is licensed under the GPL.
   Use it to make something cool, have fun, and share what you’ve learned with others.
   */
   [/php]
3. Create a « functions.php » file in the child theme folder with the following source code.
   [php]
   <?php
   add_action( ‘wp_enqueue_scripts’, ‘theme_enqueue_styles’ );
   function theme_enqueue_styles() {
   wp_enqueue_style( ‘parent-style’, get_template_directory_uri() . ‘/style.css’ );
   }
   ?>
   [/php]
4. Copy the original theme’s « screenshot.png » into the child theme folder.
5. Copy the files from the original theme that you want to modify into the child theme folder, then edit and use them.

(Reference: http://codex.wordpress.org/Child_Themes)