If you've got the pic with the 4 sides of the chest showing you'll notice the circle around the 4 characters on each side of the chest. Each circle has a break in, this tells you N, S, E or west for the 4 characters (coordinates) inside each circle. Then you need to count the number of strokes it takes to create each character starting with the top left, then bottom left, then top right and bottom right. Once you have all the characters translated into numbers and direction subtract S from N and W from E to get your final answer.
N = 8987 E = 5893
S = 3244 W = 4742
5743 1151
8 digit answer = 57431151