Those who had them on NHS can have them removed on NHS.
Those who went privately would have (or rather should have) been warned that all implants carry the risk of rupture over time, and I hope would have considered then what they would be doing for long term aftercare, including paying for replacements. Now is the time to be putting that plan into action.
One way ahead would be to sue the provider - you would need to show that the clinic or individual surgeon had been at fault in knowingly using an inappropriate implant. I don't think the manufacturer can be sued as they've already folded. If the clinic no longer exists, or goes bust because of other claims, then this doesn't look promising, though.
I read somewhere that even if NHS might remove implants, they won't be replacing them. So depending on the individual's desired end result, paying for private removal and replacement might be the best way if that can be done together, as it minimises the health risks which no doubt is important.