Regardless of how you perform updates with concrete5 version 7 if you haven't setup everything correctly to cope with this you may get the message "Maximum execution time of 30 seconds exceeded". This can leave your installation in an invalid state.
1. You need to then go the manual method plus a few extra steps:
You will need to extend the max_execution_time for PHP. If using mod_php, you can place this in your .htaccess:
php_value max_execution_time 90
or if you are using php-fpm edit your php.ini to change the Maximum execution time.
2. Make a backup copy of all your files and database (you should have done this prior to the update anyway)
3. Ensure you are logged into the dashboard
4. Using your favourite remote access tool dDelete /concrete folder
5. Delete /application/config/update.php if it exists
6. Move /updates/concrete5.7.x.x/concrete folder to /concrete
7. Visit /ccm/system/upgrade in your browser (or /index.php/ccm/system/upgrade)