I say kill your brother before he gets a chance to kill you, it's the only way to be sure. Find out where he's staying, and just wait in the closet till he gets home. Then jump out and chloroform him. Then tie him up in a cellar of some abandoned building, prefferably to a chair of some sort (metal would work best). Then cut off his fingers yelling "So, are you gonna be home after school today, you f**king f**k!?!?" When you run out of fingers, move onto the toes. Then his c**k. After you cut it off, shove it into his mouth as a gag. Make sure you're tying tourniquets beforehand for all of these things, as you don't want him to bleed out on you. And make sure you dope him up on morphine (if you live in a city, heroin is pretty easy to find and works great for this) as well, so the shock doesnt kill him. Then start working on his arms and legs, under the elbows/knees first, then finally at the hips and shoulders. At that point, you won't be able to tie tourniquets anymore, and he'll bleed to death pretty quickly. Then carve a smile onto his face, and dump his body in the river with all the tools, the chair, etc. as to wash away any forensic evidence. If done right, this could take as long as a week to do.