Apply a solution of cold water and dish soap. Remove soap residue with a damp towel; blot. If the stain persists, blot on an ammonia solution with a damp towel. Then use a peroxide solution. Let stand for a few hours. Repeat if necessary. When the stain is gone, blot on a vinegar solution. Follow with a damp towel.
For more help, watch our how to remove blood stains video.