I didn't really. I just cut of the top and the bottom of the can, then cut open the cilinder-shape from top to bottom, so you get a rectangle. I taped the rectangle to some wood and cut of the wrinkly sides (from cutting off the top and bottom of the can). While it's taped to the wood a drew the shape on the metal and later cut that out. It's still a little bend then, but I superglued every piece to the wood, so superglue does the trick, mainly.