What other part do I need to secure wiring into this housing?

LukeNag, Welcome to the Digi-Key TechForum.

You will need a contact to crimp to a wire, like 609-4456-1-ND. If you want the recommended crimper, that would be 609-2508-ND.
After you have the contact crimped onto your wire, it is inserted from the back side of the connector, and will snap into place.