You may be able to bleach them... but if you're not very familiar with bleaching and laundry, you might be better off taking them to a professional cleaner. They'll be more familiar with what's safe to use one which materials. If you use the wrong bleach on some fabrics, you won't have fabric left...I have some uniforms with some stains on them. Would it be possible to dye the uniforms white again?
Hydrogen peroxide works like a miracle on blood stains.