Edit Family Relationship

I Found our an easier and more effective way to fix this problem! Recently I’ve been trying to find a fix to this problem with my own game. I needed to change a relation in my household from brothers to roommates! I recently found an easier solution than what I’ve read! All you have to do is enter CAS, then Firstly save that household, next you select add sim from my library, the add the Household you want to edit relations between, you should have 2 of each sim, out of the newly added sims select the one you want to change relations from, change the relations, then delete the original version of the sim and duplicates of other sims in your household. Everything should be fixed and this way all relationship progress should remain the same.