The automatic first step to get your postgraduate degree is to complete a masters degree and subsequently, your undergraduate. It is preferable for the degrees pursued to be of a related fashion, thus for easy qualification to your desired postgraduate class. This is part of the journey for any person who not only loves their subject of study, but also has a passion for academics, and believes in the worth and values it proposes for the individual who chooses to pursue it. Therefore, one step at a time. Complete your undergrad, then enroll for a master. Complete your graduate course successfully, to enroll in the highest and hardest degree in the land. The previous graduations should all be done with a relative amount of effort and good merit to enable you to qualify to study for your Ph.D. in the school of your choice.