You need any black paint for fabric. Carefully read the manufacturer's recommendations to determine the amount of paint needed to achieve your desired color.
Pour the powdered dye in a small basin. Add the hot water. And leave the mixture for some time for complete dissolution of the paint.
Then, following the manufacturer's recommendations, add the required amount of water (in most cases 12 l). Stir well the paint in the water. Use warm water - it is safe for the fabric and so advises the majority of producers of paints.
Put your jeans in the basin. Constantly rinse them in solution for a uniform distribution of dye throughout the tissue. The duration of staining depends on the depth of color you want to achieve, and the directions on the package. Basically, it takes up to one hour of time.
Remove the jeans from the water. Rinse them a few times first in warm, then in cold water, while after rinsing it will not remain clear.
Wash jeans in the washing machine. Use warm water and a mild detergent. Rinse in cold water.