I've been dying my hair black with permanent dye for about five years. The last time I dyed it was four months ago, and now I want to dye it dark brown. Can I just dye over it or do I have to get rid of the black first?

Yes, you can dye it over. Permanent hair color consists of both peroxide and ammonia, and can make hair darker or a few shades lighter.

The ;ast time I got rid of jet black hair was bleach am not sure about dying over I think it would take some time

Did it turn out to be bleach blonde? Because I have the same problem but I want dirty blonde hair not BLEACH blonde! Please reply ASAP!

You should lighten it a little first even if its just to an orangish color. Color cannot lift color. Unless it's a light color and your only going a shade or two lighter.