I would really suggest keeping them separate. There is no way to "make" them get along. You can try to reintroduce them in a neutral space and see how that goes. If you have a playgym or area outside the cages that would be best. Start letting them interact in the neutral space for short periods of time and see how it goes. After several "play dates" if all goes well you could try reintroducing them into a single cage. If it does go that far make sure to make the cage as neutral and new as possible. Remove old toys, put in new. Change sides for water and food, possibly even change the position of the cage in the room. Anything to make the cage seem like new territory. Then try introducing them supervised into the cage. If it still doesn't work then separate would be better.