To remove the SIM card from your iPhone, you'll need to eject the SIM card tray with a special tool or paperclip.

To unlock your iPhone from its carrier, you'll likely need to contact your carrier directly to cancel your contract.

Turning your phone's connection off and then back on is the quickest and easiest way to try and fix your signal woes. If you're moving around from one location to another, toggling Airplane mode ...

If your new phone no longer supports SIM cards, or you don't want to use them anymore, you can convert to eSIM instead. I started my career with CNET all the way back in 2005, when the (original) ...