Some help with GIMP

[LCK]

Hey there. I'm using Sabayon Linux 2.6.22, and I cannot figure out how to add brushes and fonts to GIMP. I'm not the most computer savvy person. I download the brush, or font, I attempt to extract it, and when I try to extract it to the Gimp 2.0 folder, it says I don't have permission to do so.
Am I doing something wrong here? Am I supposed to extract it somewhere else, or do something completely different?
Any help is appreciated.

[Wait...What?]

I know there's a more direct way to do this but I don't know it off the top of my head. Here's what I'd try:

Extract the file(s) to your desktop or somewhere else you'll remember them.
Open your start menu - type " File Manager" select File Manager Super User Mode - it will ask you for your password. Now you can can navigate to your desktop, copy the files you want, then navigate to the folder you want to drop them and paste 'em in.