Choose the Sentry Omega Cluster. Choose the Hoc System. Choose the planet Virmire. Choose a party. Cut scene will begin. After the cut scene, jump in the Mako. It is time to take some Anti Aircraft down.
This is a straight forward area. There is only one path to follow. So follow the path. As the Mako comes around the bend there are some Geth Drones. Take them down. At the next bend are some Geth Drones and a Juggernaut and some rocket troopers.
Go around the next bend. Follow this straight section. At the next bend are some Drones and troopers. Around the bend is a gatehouse with some Drones and Troopers.
Follow the path past the Gatehouse. There will be a Geth Colossus. Continue until the fork in the road. Go either way they meet back up. Both also have a Colossus to kill.
After they meat back up, you will be at the next gatehouse. When Shepard arrives at the gatehouse the gates are closed. So the party will need to bail and search the gatehouse.
Clear the gatehouse of ground troops. At the far end of gatehouse will be AA Guns power controls and the gate controls. Use both controls.
Head back to the Mako. Get in. Follow the path. Around the bend is another gatehouse with the gates closed. Clear out the gatehouse of troops. At far end will be the gate controls. Use them.
Head back to the Mako. Get in. Start following the path again. There will be no more enemies. When Shepard reaches the camp a conversation will begin.
After the conversation, talk to Wrex.
After the talk with Wrex, talk to Rentola. Buy his license.
Then talk to Captain Kirrahe. He'll tell Shepard his plan. Then Shepard must choose between Kaidan or Ashley to join the Salarians. When Shepard tells the Captain he's ready, Shepard will be in the base.