Thanks for this. However, this is where my knowledge falls flat:
"and then deleting the CSS altogether and removing it from the config."
Can you expand on this? CSS from where, and what aspect of the config file? I tried editing the config file before and the whole site went wonky.
Thanks for your help
*EDIT* Sorted! I just deleted the css file and added the php file - funnily enough, just as you suggested! ;)