In the attached image, the parts of the skin that have the box around them are the uv coordinates for the weapon. All you have to do is change those parts of the skin to get a new texture on the weapon. Unfortunitely, part of the warden's leg is also used as part of the weapon, so if you change that part of the texture for the weapon, the leg color will change too. But depending on the colors you use, it may not look bad at all. Hope this answers your question. | 
