Very angry kittens to friendly cats - Socializing / Taming feral kittens

The mama of these kittens was a feral cat. The cats and the kittens were staying in an almost abandoned backyard room where lot of waste products were kept. It was not much easy to even enter the room. The kittens were not familiar with humans , so on seeing the human they would disappear very quickly as they were afraid. With the help of my friends and the building owner I managed to catch the kittens. They were hissing and meowing loudly. When I reached my home I kept them in a small room and kept it clos