How do I fix a small hole in plastic?

You can try melting plastic welding rod into the hole to fill it. Start by sticking a strip of cardboard over the back of the hole to serve as a backing. Then, hold the plastic rod 1⁄2 inch (13 mm) above the hole. Use the welder on the end of the plastic rod to melt the plastic into the hole. Once the hole is filled, turn off the welder and let the plastic solidify. Then, use a soldering iron to trim and smooth the hole so the edges are flush. Wait a few minutes to let the plastic cool and solidify and then use a file or sandpaper to smooth it out.