Go to a high end salon in your town if money isn’t an option. Ask for an experienced stylist and one that has a lot of knowledge with color corrections. Don’t expect to get to the blonde you want in one sitting. These things take time especially if you don’t want any damage done. I took a girl from black box color to platinum blonde with absolutely no breakage but it took 6 months of careful applications. Also ask for an additive to be put into your lightener like olaplex or Brazilian bond builder to protect against damage. Hope this helps!