For lazy mechanic, one needs 100ml syringe or similar, 30cm piece of hose and one liter of brake fluid.
Connect hose to syringe, put tip of hose to brake fluid reservoir, fill syringe. Remove syringe and drain content to appropriate container.
Fill reservoir to top, drive for a while, brake with heavy foot, this will mix old and fresh fluid. And repeat the process till brake fluid bottle is empty. Yes you will waste brake fluid, but you don't need to take your vehicle to garage or use time with bleeding