Obviously, for this achievement you mustn't kill January. But here is how to get Igwe and Mikhaila into your office:
Part 1:During the Main Story you will be taken to the Power Plant where Mikhaila will contact you. She can be found in the Coolant Chamber room and speaking with her will start a new quest which requires you to retrieve some booster shots. It is located in the Talos 1 Exterior so you will need to lift the Lockdown if you haven't already done so (part of the Main Quest). It is a 2 hour timed mission but you should have plenty of time. After you get the booster shots simply return to her to complete the quest.
Part 2:During the main quest you will be required to reach the Cargo Bay from the Exterior of Talos I, as you approach the Hull Breach you will get intercepted by a message from Dr Igwe. He is stuck inside a container. This will start a new side quest, you need to find the number on the shipping container and then enter the Cargo Bay to use the Docking Terminal to grab his crate. His container number is 2312, you need to enter on the Computer and then dock & unlock it as well. You will need to dock a crate as part of the main story anyway. Once you enter the Cargo Bay Dr. Igwe will greet you.
After completing both these side quests, as you progress through the story the achievement will automatically unlock after you receive a call. If you return to your office you will also find all 3 allies there, which will occasionally provide you with helpful items.