Removing Mud Stains on Jacket?

I was out side with my teacher; we were looking for rocks and I decided to stay at the first creek we passed. Any way, I was seperated from them, and then I saw this one boy climb up a rocky path across the pond, and assumed that he was going to the rest of the group. Anyway there was a sand bar between me and the path, and I decided to walk across it, then I sunk into the mud, it came up to about half way up my shin.

I was wearing my paranorman foamposites and didn't want them to get dirty, so I put them in my book bag, and borrowed a pair of boots from my teacher. In a rush, I had forgotten to take off my coat. It was a black and white Jack Skelington coat from Hot Topics, the torso was black with his face on it, and the arms were white, and now its covered with what's either dirt or clay. Any way to get it out? And as far as answers go, sooner would be better than later please.

By Rhett W.