This guide will walk you through replacing the SIM card.
Insert a plastic opening tool between the rear panel and the inner rear frame, near the rear-facing camera.
Remove the rear panel from the Nexus S.
or
Use the plastic opening tool's edge to gently pry the battery loose from its holder near the headphone jack.
Slide the SIM card down from its SIM card slot using your thumb.
Enter your pincode to see if Cash on Delivery is available in your area.