Use helping hands or a clamp to secure the position of the heat shrink solder connectors as shown in Figure 3.5. Make sure that the two stripped wire ends overlap in the the solder section of the connector. When heat is applied from the heat gun, it will melt the solder and connect the bare metal wires.
If you have not used heat shrink solder connectors before to connect wires, check out this video of the process.
If you are new to using a heat gun please make sure take precautions to you and others safe. It will get hot. Do not point it at yourself or others or other objects that are not meant to be melted.