How can the flange be cut away from the mould?

To cut away the flange from the mold, first, ensure the mold is securely supported to prevent movement. Use a suitable cutting tool, such as a utility knife or a saw, to carefully slice along the flange's edge, applying steady pressure to avoid damaging the mold. If necessary, a heat gun can help soften the material for easier cutting. Finally, clean any rough edges with sandpaper or a file for a smooth finish.