Self Deporting Planning Help Needed (Airfare, Neighbor, US to Central America)

Questions:

• can they just get a plane ticket and leave? they don't want you provide their info to this administration (understandably not trustworthy and a non-negotiable for them)
• they have a criminal record from their youth over 40yrs+ ago but did their time and should have a clean record
• they have been deported in their youth once before
• they have a valid passport from their country
• they have never been served papers to leave that they know of
• they do not have the desire to ever return
• I feel like they should have printed copies of their one way travel plans and maybe new home address memorized?

We want to make sure they are safe and are urging them to have an attorney number on hand but we don't know what else to tell them. These are the considerations I first thought of. Thank you for this community, I've read this a lot and am happy to see peoples compassion in unprecedented times.