Insert the SIM tool into the tray hole and gently push to pop it out.

Insert (gold contacts up) or remove the card.

If you’re using two SIMs, turn the tray over. Then insert (gold contacts up) or remove that card.

Push the tray back into the phone.

If you inserted two SIMs, you'll receive a notification to set them up. Swipe the notification down and tap it to manage dual SIMs. If you see 
If you’re having problems, try these troubleshooting steps.