This code snippet enables the hiding of input fields on the Easy Plugin Demo registration form

epd-hide-registration-form-fields.php

<?php

/**
 * Remove registration fields from required fields list.
 *
 * @param   array   $fields     Array of required field names
 * @return  array   Array of required field names
 */
function custom_epd_remove_required_fields( $fields )   {
    // Uncomment the array values you want to remove from the required fields list
    $remove_fields = array(
        //'epd_first_name',
        //'epd_last_name'
    );

    foreach( $remove_fields as $field ) {
        if ( isset( $fields[ $field ] ) )   {
            unset( $fields[ $field ] );
        }
    }    

    return $fields;
}

/**
 * Hide fields on the registration form.
 *
 * Make sure to mark any hidden fields as not required fields.
 * Otherwise submitting the form will fail.
 *
 * Uncomment the filter for the field(s) you wish to hide.
 * Note: These filters are only available from Easy Plugin Demo version 1.3.1 onwards
 */
//add_filter( 'epd_register_display_firstname', '__return_false' ); // First name field
//add_filter( 'epd_register_display_lastname', '__return_false' ); // Last name field