Things required to do roof flashing are: 1.Flashing material (aluminium is popular, others like copper and galvanized mmetal may also be used). 2. Staple gun 3. Metal break tool.After assembling these tools, do careful measurements and prepare the area by cleaning and drying before proceding. Now cut the material to desired length and bend it with the help of metal break tool in the middle according to desired angle. Lay down the flashing material in proper place and secure it with staple. Once installed replace the roofing material to ensure a waterproof barrier. You can also use additional roofing tar for extra protection against water back-up. Congratulations! Its done!