remove additional suffusion options in child theme with functions.php file?

Hello

I try to remove additional suffusion options in child themes only from a multisite network, I found that I should create a functions.php file in my child theme file, nothing worked cause i don’t what to write in this file, and didn’t find solution on internet.

Can anyone help me giving me the all the lines I should write, including the first lines you need when you create the new functions.php file? where to put this file?

Thank you! merci!

http://wordpress.org/extend/themes/suffusion/