To do this you'll need to have the Dominate skill, the Retrain Powers and Advanced Training upgrades and tons of Element Zero. You can get the Dominate Skill by recruiting Morinth (Samara's daughter), which means you have to sacrifice Samara in her own loyalty mission. A list of planets with Element Zero can be found below. First, purchase Advanced Training and choose Dominate. This will land you a bonus skill point, which you can use by instituting the Retrain Powers upgrade. Repeat this process for additional skill points -- one at a time! This costs 7500 Eelemetn Zero each time.