How is test tube cloning accomplished?

Easy, it's not....

"Test Tube" babies are a product of a process in which an egg and a bunch of sperm are isolated in one tube (dish) and once the egg is fertilized, it's inserted back into the female to grow. This is sometimes done with multiple eggs to increase the chances of one surviving with the sometimes unexpected result of multiple child birth. The DNA make-up of the child(ren) will be a mix of both the male chromosomes from the sperm and the female chromosomes from the egg.

"Cloning" is much different... The current process widely used in cloning is to take an egg and remove the genetic material from within, basically leaving an empty egg. You then insert the genetic material from whatever you want to clone (person, pig, etc) and shock the egg into thinking it's been fertilized and start splitting like a normal embryo. The biggest difference here is, since the only DNA / chromosomes in the egg is from the donor cells, in theory, the baby should be pretty much identical to it's donor. Furthermore, a father (sperm) is not needed in this process.