In order to solder the torn off headphone wiring, you need a screwdriver and some heat source with which you can heat its tip, for example, a working gas burner. Solder postings, proceeding as follows:
1. With a knife or just with a fingernail pick up and open the lid of the speaker
2. Push the speaker out of the earphone housing, resting against it with a wire
3. Inspect the connection points of the wiring to the speaker.
4. If one of the wiring is torn off,
then heat the tip of the screwdriver on gas
5. Apply the torn-off end of the wiring to the speaker contact and forcefully press it with the heated tip of the screwdriver, using it as a soldering iron tip
6. Place the speaker back into the earphone housing and close it with the lid
In the same way, you can check and solder, if they come off, the wiring of the microphone of the headset of the smartphone
Such special work does not require any special skills. The main thing is to act slowly and with maximum accuracy, otherwise you can not repair the earphone, but, on the contrary, break it.
Video on how to fix headphones without using a soldering iron
[media = https: //www.youtube.com/watch? v = 2V4o5AFc5II]