There has been significant work in the field of AI Ethics pertaining to how it might offer guidelines for developers to design, develop and deploy AI in an ethical way. Recently, the European Union’s AI Act has introduced a risk-based regulation approach for AI system development. However, despite the additional requirements the AI Act places on developers to ensure that their systems are created with transparency, fairness, and accountability etc., there is no formalised methodology for how this might be achieved. Drawing on the history of collaborative and emancipatory technology design in Scandinavia, this paper proposes a software development methodology founded on the ethics and praxis-based principles of Participatory Design. Integrating this approach into the established ‘Waterfall Method’, it offers developers a practical way of embedding ethics in AI development, and to thereby satisfy the requirements imposed by the new regulations.