It will probably take 2 people to do this... but if it were my bird I would prepare a pitcher of warm soapy water and one with warm, clear rinse water.
Also gather some small clean towels for drying and a tube of triple antibiotic ointment and poultry aid spray if you have it and a couple of gauze pads (like the 3x3 bandage pads) some paper towels and a few q--tips and a small pair of scissors to cut away problem feathers.
Over your sink or tub one person hold the bird while the other gently flushes the wounds with the soapy water, be careful to cover the nostril to avoid getting water in it. Cut away feathers which are trying to lay into the wound or are stuck to the torn tissue. Once flushed and cleaned out with the soapy water flush with clear water. If you don't have poultry aid (a cleansing spray) you could probably substitute a human wound spray as long as it don't have pain reliever in it. Pain relievers containing forms of "caine" drugs are controversial for use in chickens, possibly causing toxicity, not sure of the stage of research on it right now but not worth the risk given the size of the wound.
Spray liberally with the poultry aid, use the gauze pads or clean soft cloth to hold pressure for a few minutes on any active bleeding sites, blot the surrounding area dry then liberally cover with the antibiotic cream and give her a warm, quiet and darkened area to stay for a few days.
A couple of things to look at when cleaning the wound...
The esophagus (food tube) lays on the right side of the throat. It is soft and stretchy. If you can see it try to check for obvious tears or punctures in it. If minor they can be repaired with a tiny amount of super glue, being careful to not glue the esophagus shut in the process. Large tears in the esophagus would need stitched or vet level attention if you arent familiar with repairing similar injuries.
The trachea (wind pipe) lays more central/left, it is a more rigid feeling tube with rings/ridges around it. Before even pouring any water on wound watch for bubbles or hissing sounds with breathing, this could indicate a puncture in the trachea wall. If you hear or see this then dab the area with a dampened cloth until you can see well enough to track down the source. Can again be repaired with super glue.
After her first aid treatment provide her with water that has some vitamins added (Nutridrench or Polyvisol) and only soft food for a few days till you are sure her esophagus is ok.
Her recovery cage should be lined with an old towel or blanket, or even newspaper sheets, avoid wood shavings, hay, straw or any shredded bedding to reduce things sticking to her wounds.
Since she can't pick at the wound sites they can probably be left unwrapped as long as she is separated from the other birds.
