How to edit the content page fields column in the admin section? In the admin section --&gt; Content menu displays all the contents of the site.

I want to have options (or atleast to know where I have to change) for adding and removing the columns in the content section.
You can use hook_form_FORM_ID_alter() and do your changes inside that.

Example:

function YOUR_MODULE_form_node_admin_content_alter(&amp;$form, &amp;$form_state, $form_id) {
 // YOUR CUSTOM CODE GOES HERE
}