Follow the Garmin Express prompts to install the map data directly onto the SD card instead of the internal memory. Troubleshooting Common Installation Issues Garmin Expressâ„¢ | Update Maps and Devices
: Launch the app and click Add a Device . The software should detect the 4NSF and display its serial number.
Insert a compatible microSD card (up to 32 GB is typically recommended for older units) into the device's slot.
: Install Garmin Express on a Windows or Mac computer.