How to get my black hair lightened without too much damage?

Use a color remover first before resorting to bleach.

Edited to add, Oops, I missed the bit about the black hair dying! Do use colour removers before doing this. Your hair might be light enough to dye it pink under the dye. But it's also possible it's stained by the dye and even dark ginger might be impossible. You'll also need to leave a week between remover and bleach and you'll probably only need a bleach bath if it's possible. But everything else still applies!

I would use 20 vol.

Leave your hair for at least two days.

On the day before you want to bleach, cover your hair with coconut oil. Put a plastic bag over, or cling film, and then wrap with a towel or put on a beanie type hat. Leave it over night.

The next morning, make sure your house is really nice and warm. With the coconut oil still on your hair, put on the bleach. Cover loosely with cling film or a plastic bag.

Check often until your hair is light enough. A word of warning, it won't go brown. It will go ginger or yellow. Mine tends to go very quickly through the red stage, I almost never see it as I have very little red in my hair, so I generally only see bright egg yolk yellow. That would still be fine for a dark pink and still shouldn't mean you've damaged your hair.

Once you've done that and washed it off, if your hair responds well to protein, put on some kpak reconstructor and leave that on for 30 mins to an hour.

Then a quick shampoo and dye!