My daughter dyed her beautiful brown hair to a very black. She and I are both unhappy with it. I bought Salon Care Color Corrector/Remover, but am afraid to use it now. I know nothing about coloring hair. The instructions state to use any 2% or 3% Cream or Clear Peroxide Developer. What does the developer do? Does it have to be used or can I just use the color correct/remover to get the permanent dye out. I don't want to make the problem worse than it already is.

Peroxide will lighten the hair so you will need to use it with the colour remover.
But you might need to use it several times for the colour to be removed as black is a very difficult colour to remove.

If you are afraid to use the colour remover then get her to use a deep cleansing shampoo. The more she uses it, the more the colour will fade out. It will dry the hair out so be sure she applies a conditioner.