My hair is black but recently I tried dying it red but it only took to my natural hair which is the roots.I don't want my hair black no more so I thought about having it stripped to my natural haircut which is a medium brown. I want to know how many times I will need it doing and how long will it take help.

There are several "color removers" on the market. Some are bleaches (Effasol). I don't recommend them -- they're very harsh and can lead to breakage. Some color removers are "reducers" that "undevelop" and dissolve the artificial molecules and allow them to be washed out (ColorFix, ColorZap, Igora Phantom or Modulat). Here are some instructions for ColorFix:

Hair Color and Hair Care by Robert Craig Salon Products, Ltd.

Often you need more than one application and if you don't get all of the artificial color out, it can redevelop. There's a "lotion" that's included with ColorFix to check for that. In any case, if you haven't bleached over the haircolor, it's usually possible to get it out and to start over. Remember that ColorFix will leave your hair the color that it was lightened to by the peroxide in the haircoloring you used (usually auburn or orange). It will not take it back to your natural haircolor. You have to re-dye the hair after using ColorFix.

Good luck