Noted That:

• To install correctly this mootools-collapsing-categories.zip .
• Fisrt Download the mootools-collapsing-categories.zip to your computer
• Extract/Open mootools-collapsing-categories.zip to Your Computer.
• Then, Find readme.txt file inside mootools-collapsing-categories.zip and Open readme.txt .
• Now, Read the Requirements of this plugin. Which Wordpress Version and PHP Version are required to run this Plugin in Your Wordpress Site.
• Then, Follow the Tips Below.

Start the Tips:

1. First Download " mootools-collapsing-categories.zip " Plugin to your Local Computer. (Click Download)

2. Then, Login to your " yourdomain.com/wp-admin " Dashboard.

3. Then, Click on " Plugins " + " Add New " from left sidemenu of Dashboard.

4. Now, Click on "Upload Plugin" button.

5. Now, Browse " mootools-collapsing-categories.zip "  Downloaded plugin from your computer, Where you downloaded mootools-collapsing-categories.zip According to Step – 1 Above then, click on " Install Now"

6. Now, Click on " Active Plugin"

7. Then, See left sidemenu. " Moo Collapsing Categories " folder is added on left sidemenu. Now, Click on " Moo Collapsing Categories " folder.

   Noted that: If you do not see " Moo Collapsing Categories " folder on left sidemenu then, see at left sidemenu " Settings " or " Tools ".

8. Now you configure yourself oR Watch video tutorial below about  Moo Collapsing Categories Configurtions and Settings or How to work " Moo Collapsing Categories " in your WordPress site.

After Activated Plugin According to Step-6 then,

1. Go to " Plugins " + " Installed Plugin " from Wordpress Admin Panel Leftside Menu.
2. or Direct go to: https://yourdomain/wp-admin/plugins.php
3. Then, Find " Moo Collapsing Categories " Activated Plugin from Plugin List.
4. Then, Click on " Settings " from Plugin that is Moo Collapsing Categories
5. Now, Edit/Add/Config the setting and Click on " Save Changes " button,

IMPORTANT!
Please deactivate before upgrading, then re-activate the plugin.

Unpackage contents to wp-content/plugins/ so that the files are in a
mootools-collapsing-categories/ directory.

Widget installation

Activate the plugin, then simply go the
Presentation > Widgets section and drag over the Moo Collapsing Categories Widget.

Manual installation

Activate the plugin, then insert the following into your template: (probably
in sidebar.php). See the Options section for more information on specifying
options.

echo "

\n";
if (function_exists('collapsCat')) { collapsCat();
} else { wp_get_categories('your_options_here');
}
echo "
\n";