How to power off Samsung A6 without screen

The screen on my Galaxy A6 is dead. Until I possibly get it repaired, I would like to shutdown the phone, mainly to stop the alarm which I cannot turn off without the screen. I have seen plenty of instructions on how to force it to reboot (power + vol. down), and on how to hard reset it. But that is not what I want. I just want to turn the phone off. (it would be easy if I could remove the battery, but that is not possible either, and I didn't think of checking that before buying that thing...)