To adjust the handbrake on a Renault Twingo, start by locating the handbrake lever and the adjustment nut or bolt, usually situated under a rubber boot or cover. Loosen the locking nut or bolt and turn the adjustment nut or bolt clockwise to tighten the handbrake or counterclockwise to loosen it. Test the handbrake to ensure it engages and releases properly. Repeat the adjustment process until the desired handbrake lever travel is achieved. It is recommended to consult the Renault Twingo repair manual for the precise adjustment procedure and any additional steps specific to your vehicle.