Hair bleaching question

Hi I have dark brown/almost black hair.I dyed it 2 or more months ago and now am considering bleaching to get my hair as light as possible because I would like to use Manic Panic dyes now.Is 40 volume bleach the highest strength I can get?And what products would you suggest to repair the damage that the bleach and dye will do afterwards in a reasonable amount of time with minimal breakage?I hope somone has answers for me because I'd like to know

First let me say I'm not a pro, so if anyone disagrees with me on anything I say, they should pipe up and say so.  As far as I'm aware, using 40 volume peroxide to mix with the hair bleach is going to give you the maximum lightening.  Going from black dye is going to be incredibly damaging though.  You may want to try to remove as much of the dye as you can first ....but only if you're bleaching your whole head...if you're just doing pieces of it, don't do the following because it may ruin your black dye. To try to remove some of the dye, use dishwashing liquid to wash your hair, or use baking soda mixed 50/50 with your shampoo and wash it with that).  These are very drying things to do to it though, so after you use them, you should condition well and wait a day or two for your scalp oil to build up before you do any bleaching (protects your scalp from the chemicals).  Then you would bleach it and do your manic panic.

There's no way to repair the damage after you bleach it.  Hair is dead and its not going to get healed or repaired by anything you do.  Using a heavy silicone conditioner will help the bleached hair feel smoother and tangle less though by putting a silicone coat on each strand (that would be any conditioner with a lot of words in the ingredients that end in "cone").  Remember that you aren't supposed to condition between the bleach and the manic panic, you might be tempted because your hair will feel like straw.  Good luck.  Oh, and test strand first because it IS possible to bleach your hair to the point where it just all breaks off, especially going from such a dark color.
 

Sure, you can do it like that.  Just eyeball half and half, it doesn't have to be exact.

Well, like I said, these are things to try, it often depends on what dye was used and since its been 2 months for you, maybe not much will help, as you say.