What you need first is some fine wire. A small paper clip will do. Drill out holes into the shoulders and insert a length of wire. It gets a little tricky here, for you need to check porportion. If a person stands upright ( at attention for example) his/her finger tips should end at the mid thigh point of the leg. The length of the forearm, from wrist to elbow is equal to the length of one's foot. So with that in mind, you can reattach the hands to the end of the wire and check to see if the arm is the right length. Then bend the wire at the point where you think the elbow should be, and then set the pose of the arms. You now have a figure with two wire "skeleton "arms. Take some type of putty. Miliput or Magic Sculp are two types that I have found to be quite useful. Apply a rough layer on the wire to flesh out the arms. After this dries, and you're satisfied with the looks of everything, you can add another layer for the clothing. A selection of rounded off toothpicks or wooden BBQ skewers will serve nicely as sculpting tools. Try to sculpt in the folds of the cloth, taking care to represent the creases in the elbow and armpit areas. Make the folds consistant with the type of cloth your figure is wearing. Larger folds for heavy wool, thinner, more numerous folds for light cotton materials. A few scribed lines here and there for seams, and Voila! Brand new arms, in any pose your heart desires. Buttons can be added with small "balls" of putty pressed gently into shape.