First, get your other hens away from your broody so she can do this in peace.
I would let the one with the teeny hole get on with it unassisted at the moment. If you interfere and the blood vessels are not retracted, you may cause it to bleed to death. As for the one half out, do you mean it was already half out or the 'crushing' has caused it to end up that way? Either way, you may need to very gently help it out but again, be careful of blood vessels and make sure the yolk has been absorbed. If the shells are badly broken, this may cause the membranes to dry out too quick and 'shrink-wrap' the babies so a fine spray of warm water may be necessary and you may need to do it more than once.
You may also need to prepare for the possibility of losing the chicks or that interference may cause rejection. If it is looking like the chicks are going to need persistent help, you are better removing them from mum entirely, letting her sort other eggs and then if you get viable chicks from the removed eggs, sneak them back under her at night once they are fluffed up and dry.
How are things looking now? x