A & B Bleach

Apply Part A ( Sodium Carbonate ) to the substrate, and leave for 10-15 minutes. Do not let the solution rest too long before applying Part B ( Hydrogen Peroxide ), as Part A can darken some tannin rich woods such as Cherry and Oak.
Apply both Part A & Part B sparingly with a separate Fiddes Bleach Brush. A single application should be adequate, however if necessary repeat the process until the desired effect is achieved. Do not mix Part A and Part B together in solution before application.
Once the substrate is dry, neutralize well with Acetic Acid (white vinegar).
When completely dry, lightly sand the surface. Surface must be clean and completely dry (not just surface dry) before refinishing.
Incomplete drying and retained subsurface moisture can cause finish adhesion failure.