How do I go platinum causing least damage as possible?

Hi there. If you hair is virgin, your best plan would be to go in with a highlift tint to lift your natural up as light as possible. From there, you could do heavy highlights all over your whole head. Afterwards, a toner would be applied to balance out the color and make it a soft gorgeous platinum blonde tone. Please note, however, that going from as dark as you are will require your commitment to get your roots done every 4 weeks without fail. Otherwise you will run in problems with what we call "gold bands". Trust me, you don't want that. Hope this helps. Good luck!