Thanks, I was able to add a folder under the main directory using FileZilla. So, I now have a file listed as ftp://USERNAME@ftp.DOMAIN.com/.php/5.4/phprc (I've replaced username and domain with placeholders) I essentially copied and pasted the following (from the Wiki article) into notepad for the phprc file:
upload_max_filesize = 64M
post_max_size = 64M
max_execution_time = 500
max_input_time = 500
Then, I saved/uploaded it, and it appeared to successfully update it on the server. However, when I check the current PHP Post Max Size (in System Info for Headway in my WP dashboard), it still is showing only 7M.
Did I do something wrong? Or is there an extra step?