[Theme: Pink Touch 2] Issues modifying child theme

Hi,
I’ve added in a child theme based on Pink Touch 2, I’m making a change to the “pinktouch_post_data()” function to change the layout of some of the extra info. I can change this in the parent theme to accomplish what I’d like but obviously I’d prefer to make this change in the child theme.
I’ve searched around the internet and people talk about add_action and remove_action. My issue is that this function has no add_action so I don’t know how to remove the parent themes version of the function. Having them both in gives an error.
I could rename the function in the child theme to something else, but then I have to change all of the post template pages aswell (which I’d also like to avoid).
Could someone suggest how I can simply override this function in the child theme so it’s picked up correctly?
Thanks

http://wordpress.org/extend/themes/pink-touch-2/