Well, my mother is a retired hairdresser after 40 years, and I've been living with it my whole life ;) so I feel qualified enough to answer this question.
First, you ought to wait at least a week before dying again. Second, each time you wash your hair, a bit of that dye will fade out...so wash it every day, and do the "rinse and repeat" and you'll see improvement soon. Make sure you are using a good conditioner.
Second, in order to lighten hair, you generally need a lightener (bleach.) I don't recommend this for anyone's hair at any point, because it really just destroys your hair, but you especially do not want to bleach your hair. Only a professional stylist (and even not some of them!) will understand how to get you to the lighter shade you want. Please don't try this on your own!
After your dye is completely faded out...probably in six weeks or so...you can dye your hair again. I'm not sure what color you were trying to get, but if your hair is dark, you need to go several shades lighter than your desired shade in order to get the results you want.