How do I change the PHP settings in Plesk for a website on my server?

It is assumed that you are using Plesk as a Service Provider.  If you are using Plesk as a Power User, switch to Service Provider:

1. Go to the 'Server' tab
2. Go to 'Interface Management'
3. Go to 'Panel Appearance'
4. Click 'Service Provider'
5. Click 'OK'
6. You will now be in Service Provider mode

To change PHP settings for one site:

1. Click on 'Subscriptions' in the left-hand menu
2. Select the subscription you want to change settings for
3. Click 'Customise' in the top menu
4. Click on 'PHP Settings' tab
5. Enter in the custom values you want for the following settings:

memory_limit
max_execution_time
max_input_time
post_max_size
upload_max_filesize
safe_mode
safe_mode_include_dir
safe_mode_exec_dir
include_path
session.save_path
mail.force_extra_parameters
register_globals
open_basedir
error_reporting
display_errors
allow_url_fopen
file_uploads
short_open_tag
magic_quotes_gpc

6. Click the 'Update and Lock' button
7. The changes will be saved for that site