Change name of a post type without losing posts

Question

I have made a site that uses custom posts types for a projects section.

I need to change the post type from 'projects' to 'galleries' but as I have already uploaded a bunch of projects was wondering how I would do this with as little as possible hassle (I do not want to have to re-upload all the images and text etc)

I found a few articles that tell me to do a SQL query to rename the posts

UPDATE  `wp_posts` 
    SET  `post_type` =  '<new post type name>' 
    WHERE  `post_type` = '<old post type name>';

And this one for the taxonomy

UPDATE  `wp_term_taxonomy` 
    SET  `taxonomy` =  '<new taxonomy name>' 
    WHERE  `taxonomy` = '<old taxonomy name>';

I just have no idea what I am supposed to do with this code. If it is SQL do I run it in a php file or is there some sort of 'terminal' that can be found in the WP dashboard or cPanel of my site?

Below is how I created my post type (Not sure if this helps)

function create_my_post_types() {
    //projects 
    register_post_type(
      'Projects', array('label' => 'Projects','description' => '','public' => true,'show_ui' => true,'show_in_menu' => true, 'menu_position' => 8,'capability_type' => 'post','hierarchical' => false,'rewrite' => array('slug' => '','with_front' => '0'),'query_var' => true,'exclude_from_search' => false,'supports' => array('title','editor','thumbnail'),'taxonomies' => array('category',),'labels' => array (
      'name' => 'Projects',
      'singular_name' => 'Project',
      'menu_name' => 'Projects',
      'add_new' => 'Add New Project',
      'add_new_item' => 'Add New Project',
      'edit' => 'Edit',
      'edit_item' => 'Edit Project',
      'new_item' => 'New Project',
      'view' => 'View Project',
      'view_item' => 'View Project',
      'search_items' => 'Search Projects',
      'not_found' => 'No Projects Found',
      'not_found_in_trash' => 'No Projects Found in Trash',
      'parent' => 'Parent Projects',
    ),) );  

} // end create_my_post_types

Answer 1

If you have CPanel access, you can look for PHPMyAdmin and run the SQL code there.

1. Go to PHPMyAdmin.

2. Select your wordpress database from the left.

3. RECOMMENDED: Backup your database first, by going to the export tab at the top and doing a quick export.

4. Select "SQL" from the top tabs.

5. Copy your SQL queries in the huge textarea, and click Go.

Hope it works!