This is a very common problem. Do you always wake at the same time and if so, what time?
Firstly, I would take Deep Sleep Vogel's natural sleep aid. It has been shown to help people both get to sleep, and stay asleep. You could take it before bed, or when you wake, or both.
There are lots of issues that contribute to early morning waking, such as: stress; unstable blood sugar levels; late night meals, etc.