I have two sims that are married and have a toddler and a baby. Now I wanna..

The first thing you should know is that from what I can tell you can not move a married sim into another house, and you need to do that to demolish the house they are in. But if you want to get them divorced, then build another house for one of them to move into, then try to move them in together again then here is what you do. (Note that I have never divorced Sims before so I'm not completely sure how it works, but there are other questions and answers on this site that could probably help you.)

First you need to move the one divorced parent into the better house that you wish to move all of them into. Now you need to make the house you wish to get rid of vacant, so no one is living there. That means moving the divorced parent still living in the old house into the better house with the other parent, and bringing the kids. Once that is done click on the house you want to get rid of, which should now be vacant, from The Town Map and click demolish.

I believe, if I recall correctly, all you have to do is move the family to another available house, go back and demolish the one ou wanted to, then just move the family bak in, Thanks too the livin large update, you can move the whole family