People can change their black hair to blonde hair by bleaching. It is a process that can take several attempts, depending on the shade of blonde an individual wants to achieve.
People who want to take their hair more than two shades lighter should seek the help of a professional stylist rather than attempting to do it at home. Bleaching an individual's hair is an involved process, and an inexperienced colorist can damage the hair. A licensed stylist can ensure the bleaching is done properly and evenly to minimize the damage, and to ensure the coloring is correct. Going from black to blonde usually requires more than one session, which means individuals may need to wear hats and scarves until the process is complete.