After those hours are over, you can start the taming process. Start simple and easy, just putting a few treats in your hand and letting your gerbils eat them. Don't be surprised or discouraged if your gerbils run and hide. They'll get used to you. After a week, your gerbils may decide to eat their treats in your hand. Don't continue to the next step if they still run and hide when you come over.
Don't worry if you are nibbled. Gerbils will do this to taste you, and see if your food. When they figure out that your not, they shouldn't do that anymore. Don't blow in your gerbils' faces. That can cause seizures in some gerbils. Please refer to this guide for gerbils who bite.
If your gerbils are doing good with step one, it's time to move on. This time, when your gerbils come over to eat treats, gently scoop them up with two hands cupped around them. Sit on the floor and put the gerbil on your lap. Your gerbils should eventually trust you enough to climb up your arm when they want to be let out.