Adding weapon sprites

Just to clarify I am new to using RPG Maker MV still. I am attempting to add specific weapon sprites to my heroes but not sure how to even start it. I looked through the menus and found the Weapon tab under Database. The only sprite you can add in is the icon, not for the actual SV-battles. Do you need to physically go into PS with your pre-generated PCs battle sprites and add the weapon to each individual battle sprite or is their an easier way?