Power off the phone and find the tiny hole on the left side of your phone (screen facing you). Insert the SIM extraction tool that came with your phone into this hole. Apply slight pressure to pop the SIM tray out of the slot. The video below shows how to remove the SIM card. The video shows a dual-SIM SIM tray, the process of SIM tray removal is the same for single-SIM phones.

https://www.youtube.com/watch?v=NyzgY0H2kJc&t=24s