Letting something go is an art. It cannot be learned in a day. But with constant effort and determination, you can master it. Let me emphasize this point with an illustration.
In some Asian countries following trick is used to catch monkeys. A small hole is made in the coconut and the size of the hole is such that a monkey’s hand can enter when open but cannot exit when clenched. They place a sweet inside this hole and keep the coconut in a suitable place. The monkey, enticed by the sweet, puts his hand inside. But he cannot take it out because his fist is clenched with the sweet. A simple way to escape is to let go of the sweet, but very rarely a monkey does this.
So the trick lies in the ability to let go of the sweet, or your desire. This is the shortcut to unconditional happiness.