Things You'll Need
Instructions
Download LEGO Factory from the LEGO shop. This software is free, and once it's installed on your computer you can design your own LEGO models.
Open the program and build your custom LEGO model. You can choose the block size and style, color and more. Drag and drop the blocks into the main space and build your custom LEGO model in the shape of the weapon you want.
Upload your personal design. Go to Lego.com and upload your design. Once it's uploaded you can purchase the set, and it will be sent to your home.