Can I Change Custody?
In Oklahoma the answer is yes. If your ex has custody and you can show a change of circumstances of the custodial parent that such that the children would be substantially better off if custody were transferred to you, then the court will consider a change of custody. If you share joint custody of your kids the court can terminate the joint custody plan whenever the court feels like it isn't working. Once the court does that then it will decide on a new custody arrangement based on the best interests of the children, so if the children would be better off if custody were granted to you, then that is what the court will do.
Sadly, some people don't fare well after a divorce. The emotional toll of the severed relationship along with the stress of being a single parent causes radical changes in many people. Some people start heavily drinking or doing drugs to deal with the change while others, out of desperation, hitch their wagon to somebody new. Oftentimes this negatively affects your children and astoundingly, most of the time the changes are relatively easy to documents. With a new jerk spouse/step-parent it can be as easy as getting them to testify.
Should I Change Custody?
Stability is an important factor to the healthy development of a child, but negative circumstances, no matter how stable, will do continuous damage to them. If you believe that your children are being hurt by the changes in your ex-spouse's lifestyle you need to document the changes and consult with an attorney right away. Even if you don't win for technical legal reasons or the judge is just stuck on the fence the court will often give a "wake-up call" to the custodial parent and that gives them the perspective they need to do right by the kids. Just letting your ex know that you're watching and that you've got your kids' back will often correct a lot of stupid problems.
How do I Change Custody?
The way to change custody is by calling a great family lawyer and filing a Motion to Modify or Motion to Terminate Joint Custody. The Motion will start the procedural ball rolling which is important. It's easy for the process to be delayed so the sooner it's started the sooner it's done. I'm happy to talk about Custody Modifications any time.