The safest way is to open the phone and get to the SIM card that way.
Trying to remove it from the outside will most probably only damage the card reader. Also doing it this way could possibly cause electrical problems, even if the phone is switched off, because the card may be shifting across the board and shorting out things as it is being moved, which normally would not happen if it were in a tray.
There is always power available on the systemboard when the phone is off. The power on/off button is not a power isolating button. Its function is to signal the OS what the user wants to do. Think of the phone being in an extremely low power state when off and that it is not isolated from any power supply i.e. the battery
Here’s a teardown video for the phone which may help.
If doing this yourself seems too daunting, contact a reputable, professional mobile phone repair service and ask for a quote. Given how new the model is, in the end it may be worth doing it this way as the repairer will have the necessary tools and expertise to do the repair. Also they will bear the responsibility if it goes wrong.