Cut off as much as you can without hurting yourself or causing further damage. Do NOT wear bandaids as they will keep the skin too moist and bacteria just love moisture! Keep it clean and dry and apply a very small amount of peroxide daily just to be sure the re is no infection present. If the peroxide does not 'bubble', then there is no infection present. Just keep it clean and dry and try not to bump the exposed nail bed. If you feel you MUST cover it, wrap it with gauze and use the ends of he gauze to tie it in place. Gauze will absorb any excess moisture and allow it to evaporate. If you get the gauze wet, get a fresh piece and tie it on. Never allow it to remain wet.