They super glued the parts together. Let that dry. Then they put common nails on top of the broken piece and used a soldering iron with a flat type tip to heat the nail up and melt it into the plastic. It doesn't matter what glue you use as for the iron you need to get one that can heat up hot enough to melt plastic. The white glue type stuff is a two part plastic apoxy such as J.B. Weld but made specifically for plastic.
