If you want to dramatically lighten your hair colour, you need to use a bleach such as peroxide. With peroxide you can strip the colour off your hair. You can then dye your hair to the lighter colour of your choice. Lightening hair is a 2-step process -- removing hair colour and then colouring the hair. Because 40 volume peroxide is strong you need to be very careful when using it.
Cover the floors and countertop with dust sheets or old towels. This protects them from bleach stains and discolouring. Put an old towel around your neck to protect your clothes.
Open the window to get plenty of fresh hair. Peroxide has a strong odour so it is best to use it in a well-ventilated room.
Put on plastic gloves. They usually come with the peroxide kit.
Open the container of powdered bleach and pour it into the plastic mixing container that comes with the kit.
Pour the 40 volume peroxide cream developer into the mixing container a little bit at a time. Mix the bleach powder and the peroxide using the brush that came with the bleaching kit. Stir well, adding in more and more of the peroxide to make a mixture that is not to runny or to thick.
Place the brush into the mixture. Then apply the mixture evenly throughout the hair.
Leave the peroxide on the hair until you have the colour you want. Don't leave the mixture on your hair for more than 30 minutes to avoid damaging the hair and scalp.
Rinse out the bleach thoroughly in warm water. Then use a gentle shampoo to wash out all the chemicals. Dry hair as usual.
For best results have a professional hair colourist bleach your hair.