How do you clean blood stains off of a WWI reenactment uniform?

I took part in a WWI reenactment yesterday and well things got a little bit too realistic. Now I have some blood on my German reenactment uniform. Don't feel too bad for me about this. First of all, it wasn't my blood, and believe me, I was one of the lucky ones! I'd put up a picture of it, but it's pretty bad and people would probably think I'm a troll and will have this question deleted. I'm sure this kind of thing happens all the time in the war reenactment community. The good news is we got some awesome footage of it and hey, it wasn't nearly as bad as the real WWI!