Connect via FTP. Open /conf_global.php. Just above the closing ?> tag, on its own line add:
$INFO['status_sidebar_show_x'] = '10';
Save the change, adjust the 10 if you prefer a different number. The default if that line is missing is 5.
Note: Ensure that conf_global.php is not writeable after you've re-uploaded it, typically you would CHMOD it to 644 or 444 if possible. Never leave it at 777.