According to Osho, there is no 'how' to surrender. Simply see, with total honesty, the stupidity and misery of the ego and why you cling to it. When you perceive that its promises never deliver and only breed suffering, clinging ceases by itself. Then surrender happens naturally—it's just the absence of ego—not another technique or belief to grasp.
Look closely at how holding onto “me, me, me” keeps hurting you; when you truly see it gives nothing, you stop holding it, and surrender shows up on its own.