Particle help! (1.6.2)

Hi everyone. I was just wondering if anyone can help me out and maybe a lot of others, because I can't figure out how to edit them. Currently, I'm working on a 512x512 HD Photorealstic texture pack and I want to edit EVERYTHING (including sounds). So at that, I would like some help with the particles.png in the particles folder. If anyone could paste a picture with a little guide that would be GREATLY appreciated! Thanks!