The tools you need is a wrench to loosen the brake fitting. All you need is fresh fluid, and then get to bleeding the brakes. When the reservoir starts going down, refill it with fresh fluid. This will do better the more the old fluid is other than clear. You keep bleeding/refilling with fluid until you start getting clear coming out of the wheel you're working on. Tighten the brake fitting, and move to the next wheel. Do that all the way around and once all four bleed clear fluid out, you've flushed the system.