If helmet removal is mandatory due to airway arrest, what is the proper medical standard two-person helmet removal technique (双人头盔脱卸法)?

1. One person pulls the helmet with their foot while the second person pushes the victim's shoulders
2. Rescuer 1 maintains manual inline cervical stabilization from below by holding the mandible and occiput; Rescuer 2 unfastens the strap, gently expands the sides, and tilts the helmet backward/forward over the nose without moving the neck
3. Both rescuers pull the helmet simultaneously in opposite sideways directions
4. The helmet is pried open with a crowbar while twisting the victim's head 90 degrees