What does Kosovo needs to do in order to become a fully independent country? [closed]

What are the steps that Kosovo, or, if it's not about them, other countries must do, so it can be recognized as an independent country?

In 2008, Kosovo unilaterally declared its independence from Serbia.

As shown in wikipedia, currently it is a partly recognized state. Most of the EU nations (23/28) did recognize, but there are still Spain, Cyprus, Romania, Slovakia and Greece who did not.

Also, in the UN, there are many countries that do recognize, as well as many that do not (it's around 50-50).

Is actually the most important vote of Serbia, since Kosovo is/was part of their territory? Or even if Serbia never let it apart, can it be done by voting of the other countries?