The mind is formless, but we allow it to become occupied by habitual thought patterns. So, how can we let go? I will show you. If I hold an apple in my hand but reach for a pencil, I will naturally let go of the apple. My mind and muscles will do this automatically. If you generate an angry thought, how can you let it go? You let it go by generating a happy thought. When a happy thought arises, you will automatically release the angry thought. It is essential that you force yourself to do this in the beginning, simply because you lack practice. This is a positive, active way of letting go.
by Master Miao Tsan