Want blonde hi-lites

I want to go blonde but slowly since I''m dyed dark brown (fading from black dye). I don''t want to be blonde right away. From dark brown I''d like to go to light brown, then from light brown to medium/dark blonde and then add platinum blonde highlights on this medium blonde base. Also, only go in for root touchups every 6-8 weeks after achieving platinum blonde highlights. Is this reasonable? Or will it ruin my hair this way? I had bad at home bleaching jobs in the past and I want to avoid that and to achieve somewhat more natural looking highlights while maintaining my hair length.

Thanks