If it was me, I'd pluck out the damaged feathers - but I have done it many times before.
A vet (preferably avian) would be the safest option for anyone not having done this before as it can be dangerous for the bird.
But if you really want to have a go yourself: get a pair of tweezers, some disinfectant and a soft towel. Go into the bathroom and hold the bird in the towel, with the tweezers, get a grip as close to the shaft of the broken feather and (make sure you hold the wing firmly - might need 2 people) in one swift motion pull the feather out. Bathe the wound in disinfectant straight away and do the same on the other side if it's broken. There will be lots of blood but if your bird is strong and healthy it will clot pretty quickly - as long as it doesn't do anything silly. If possible wrap the bird in the towel afterwards and put it in a smallish box and cover the box to encourage it to rest. Leave it there for a couple hours or so then get it out and check that the clotting has taken - don't knock the wound or it will start bleeding again!
This is very risky for the bird though and it well could go into shock and possibly die if you don't handle it properly. If you've not done it before I really would rather a vet (preferably avian) do it and show you how to do it should you need to do it again.
*None of us here on Bird Crazy are vets and any advice we give is from personal experience only - not accredited training from a veterinary college.*