Steps to add your brand to the different items in this pack :

• Go to the the UVs folder and open the jpg of the product you want to add your branding to in your favorite image editor
• Add your branding on top of it, remove any background and save you image as a png with transparency
• Open the blender file containing all the items in the pack and select the associated item
• Go to the shader, and replace the image texture by your new png