Follow these instructions from Robert first:
1. download this: https://www.phpbb.com/files/release/phpBB-3.2.0.zip
2. unzip it to your computer somewhere
3. using your ftp, remove all of the files/folders from your message board folder except for the config.php file and the ext, files, images and store folders.
4. using your ftp, upload all of the new 3.2 files and folders except for the config.php file to the message board folder on the server.
5. open your config.php file, change this line $dbms = 'mysql'; to this: $dbms = 'mysqli';
6. in your browser, go to: https://your_message_board/install/
7. click on the tab that says Update and then choose update database only and submit.
Then to correct time do this:
(For some reason I had to skip step #5 to get this to work) You can try both ways with #5.
If you have a WHM cpanel access:
I increased my time for execution to 150 sec.