The nucleus of each egg is sucked out. Then, cells, which are taken form the cloning candidate, are replaced into the eggs. These are zapped with electricity to cause to fuse and divide to form embryos. The embryos are inserted to a woman's womb. It is seems to be technically easy to do it.
Scientist needs surrogate mothers up to fifty to get nine to ten pregnancies.
This number of pregnancy is amazing. Even getting ten pregnancies in a normal way is coming upon a mother's body, much less in an artificial way. Cloning for human reproduction is banned in some countries including Japan and most of Europe, WHO and Vatican. Even though, people know that human cloning is terribly inefficient and risky, some are interested in it. First, those people would be couples who are infertile including old people.