How can I change my dyed black hair to light brown?

I dyed my hair black about 2 1/2 mos. ago and I want to go back to light brown with highlights. I have done highlights myself with the cap. Any suggestions on dye brands? How should I do this to have the best outcome. Im thinking a pretty light brown with blonde highlights..How can I change my dyed black hair to light brown?
Use a clarifying shampoo for a while (a week at least) to strip some of the black. Then if your dying it yourself, but the dye that is one shade lighter than you want it to be.