Change strings used in Genesis Portfolio Pro CPT - https://www.damiencarbery.com/2018/03/change-settings-of-a-cpt-custom-post-type/

portfolio-change-menu-text.php

<?php
/*
Plugin Name: Change Genesis Portfolio Pro settings
Plugin URI: https://www.damiencarbery.com
Description: Change the settings for the Genesis Portfolio Pro CPT.
Author: Damien Carbery
Version: 0.1
*/


add_filter( 'register_post_type_args', 'dcwd_change_cpt_args', 10, 2 );
function dcwd_change_cpt_args( $args, $cpt_name ) {
	//error_log( "CPT Name: $cpt_name" );
	if ( 'portfolio' == $cpt_name ) {
		//error_log( $cpt_name . ': ' . var_export( $args, true ) );
		$args['labels']['name'] = 'Case Studies';
		$args['labels']['menu_name'] = 'Case Studies';
		$args['labels']['add_new'] = 'Add New Case Study';
		$args['labels']['add_new_item'] = 'Add New Case Study';
		$args['labels']['edit_item'] = 'Edit Case Study';
		$args['labels']['all_items'] = 'All Case Studies';
		$args['rewrite'] = array(
			'slug'       => 'case-studies',
			'with_front' => false,
		);
		//error_log( $cpt_name . ': ' . var_export( $args, true ) );
	}
	return $args;
}

portfolio-cpt-settings.txt

portfolio: array (
  'labels' => 
  array (
    'name' => 'Portfolio Items',
    'singular_name' => 'Portfolio Item',
    'menu_name' => 'Portfolio Items',
    'name_admin_bar' => 'Portfolio Item',
    'add_new' => 'Add New',
    'add_new_item' => 'Add New Portfolio Item',
    'new_item' => 'New Portfolio Item',
    'edit_item' => 'Edit Portfolio Item',
    'view_item' => 'View Portfolio Item',
    'all_items' => 'All Portfolio Items',
    'search_items' => 'Search Portfolio Items',
    'parent_item_colon' => 'Parent Portfolio Items:',
    'not_found' => 'No Portfolio Items found.',
    'not_found_in_trash' => 'No Portfolio Items found in Trash.',
  ),
  'has_archive' => true,
  'hierarchical' => true,
  'menu_icon' => 'dashicons-format-gallery',
  'public' => true,
  'rewrite' => 
  array (
    'slug' => 'portfolio',
    'with_front' => false,
  ),
  'supports' => 
  array (
    0 => 'title',
    1 => 'editor',
    2 => 'author',
    3 => 'thumbnail',
    4 => 'excerpt',
    5 => 'trackbacks',
    6 => 'custom-fields',
    7 => 'revisions',
    8 => 'page-attributes',
    9 => 'genesis-seo',
    10 => 'genesis-cpt-archives-settings',
  ),
  'taxonomies' => 
  array (
    0 => 'portfolio-type',
  ),
)