If you send a complete upper which needs to be disassembled, you need to select this service. We disassemble the upper into major components. As standard, we do not disassemble the port door, forward assist, gas block, and front sight post. If you want everything disassembled, note as such in your order. We will NOT attempt to install or remove any Chinese parts. If you are sending a unique/proprietary upper with a rail system like the URX, or any other glued together system, this fee is DOUBLED.