Add the sample code below to your child theme's functions.php file or in a site specific plugin. Then change REPLACE ME to the new messaging that you would like to display for the View Details button to your attendees/registrants.
<?php
//* Do NOT include the opening php tag
//* Adjust view details button text in Event Espresso 4
add_filter ('FHEE__EE_Ticket_Selector__display_view_details_btn__btn_text', 'ee_view_details_button');
function ee_view_details_button() {
return 'REPLACE ME';
}