Hair Dye Answers

If you do, can you give me the directions for the applicator? It came with 2 bottles. I used the one to get rid of light, now I want to use the other one to get rid of the dark lol.
Also will head & shoulders remove hair dye?
I died my hair a really dark brown (kinda black) over really gold, light brown hair. (its ugly on me) Its permanant but every time I try to dye it medium brown it washes out right away to the gold. Will this be the same way?
Thank you!