Besides the PHP Selector, you can change settings per folder with a small text file.

Here's how #

1. In your site's folder (public_html), create a file .user.ini, e.g. via the File Manager.
2. Put one setting per line, e.g.: memory_limit = 256M and upload_max_filesize = 64M
3. Save the file. After a few minutes the new values are active.

Use a phpinfo page to check the values are right, then delete that page again.

Stuck? Open a ticket, we're happy to help.