Are you saying that the directions on https://support.microsoft.com/en-us/help/4056486/surface-insert-sim-card-surface are not working?
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- Place your Surface Pro X screeen on a table and lift the kickstand to reveal the SIM door.
- Insert the included SIM ejector tool into the small hole on the SIM door to detach it.
- Push your SIM card into the SIM card slot until it clicks.
- Slide the SIM door into place, then press down until it clicks.
- To use your SIM, select Start > Settings > Network & Internet > Cellular , then under Use this SIM for cellular data, select SIM1.
- On the taskbar, select the Network icon (, , or ) and make sure your SIM card mobile operator is listed.
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