Uriahs Victor on "How to edit php files from child theme"

Before you start to read please do not send me a link to the codex, i have looked and tried but i cannot get this to work so please explain and help me here.

I currently have a child theme where i could edit the css andit works fine, most times i just need to add !important after the line in the styles.css.

my problem is that the theme that i am using has some places where words are used that do not apply to me e.g the placeholders for address, and other little things that i want to change.

I know where exactly to make those changes in the parent's .php files but i do not want to mess with them because of fear of my changes being lost after the theme or wordpress updates.

Ok heres the drift for one of my big problems.

currently im using the WP social plugin with my website and it inputs right above the default code for registering on my site:

Link to image

i know how to fix it, however;

The original file is located: /wp-content/themes/ProjectTheme/lib/login_register.php

i made a copy with the exact path in the child theme: /wp-content/themes/ProjectTheme-child/lib/login_register.php

but when i edit the one in the child theme the changes do not override the parent. Please tell me what i am doing wrong, this is my functions.php withing the child theme:

<?php
/**
 * Enqueues child theme stylesheet, loading first the parent theme stylesheet.
 */
function soaringleads_custom_enqueue_child_theme_styles() {
	wp_enqueue_style( 'parent-theme-css', get_template_directory_uri() . '/style.css' );

	}
add_action( 'wp_enqueue_scripts', 'soaringleads_custom_enqueue_child_theme_styles', 11 );

?>

Do i need to add something in it to be able to edit that login_register.php?

Regards.