how do I download brushes for GIMP for fedora Linux???

I have GIMP 2.4 for Fedora Linux. I am definitely not a computer person but I can do all the basic crap haha I mean obviously, im in highschool. but I cannot figure out how to download and use brushes. when I try to download them, a window comes up that asks what firefox should do with the file? and theres the ‘open with’ option, and ‘save to disk.’ I know I want to click ‘open with’ and I found the GIMP2.4 folder, and then the brushes folder, but it wont let me just save the file into the folder. it makes me click on one of the pre-existing files, and even if I try to save it into one of the already-there brushes, it wont work. can anyone who is familiar with fedora Linux and GIMP please help me???