Hi Lucky009,
A 580 is slightly above-average score (the average score on the Official GMAT hovers around 540-550 most years), so it's understandable why you would want to retest. I'd like to know a bit more about how you've studied so far, so that I can offer the most useful and pointed advice possible:
1) How long have you studied?
2) What materials have you used during your studies?
3) How were you scoring on your practice CATs (including the Quant and Verbal Scaled Scores)?
Using this Official Score as a 'baseline', you're likely going to have to improve in BOTH the Quant and Verbal sections to hit your goal score. As such, you should be looking to invest in new GMAT materials that will help you to improve in both of those sections. Thankfully, the GMAT is a predictable, standardized Test, so you CAN train to score at a higher level.
GMAT assassins aren't born, they're made,
Rich