No. Reducing the amount of blood in your body will not reduce your high blood pressure. The problems that cause the high blood pressure are still there; and, when the level of your blood returns to normal within a few days, your blood pressure reading will still be the same as before.
There is absolutely nothing to be gained and a life to lose if you try to use this as a method of reducing your blood pressure.
Visit a doctor and supplement this with a trip to a naturopath for both medicinal and natural support to reduce your blood pressure safely.