I don't know if this will work for family reunion since i used it for ship shape and good karma but this video could help you out.
Shoutout to
Andytop97 for showing me this video.
Follow all the instructions and the cheevos should be yours, by the way, i wasn't paying attention on General Briggs with Menendez, and Salazar slammed with his weapon on briggs head and he was still alive and i got the 2 needed cheevos anyway. Good luck and have fun.