Not necessarily in this order:
1.) Gather all of the evidence of my [Nick's] crimes. Send it to the police, Aaron's lawyer, and Monty's lawyer.
2.) Divorce Kayla. Tell her that she must do better and care for the kids while I [Nick] take the fall for the best of the family. Give Kayla and other family members majority if not full custody.
3.) Kick out April. Delete her information from my [Nick's] contacts. Initiate a restraining order against her for the whole family if she attempts to return.
4.) Liquidate assets to pay Monty. Post a video and messages on all social media apologizing for the incident, retracting the statements, and offering to help Monty in future proceedings against others who continue to spread the defamatory statements.
5.) Have a sit down with the kids to explain why things are happening, why dad has screwed up, and how they should avoid this in the future for themselves and their partners.
6.) Turn myself [Nick] in. Plea guilty but insist on strict measures in the agreements such as long-term rehab, continual drug testing, some amount of jail time, things such as that to ensure that real Nick gets a message.