Lexmark CS943
Turn off the printer.
Apply isopropyl alcohol to a damp, soft, lint-free cloth, and then wipe the surface around the USB port.
Install the wireless module.
Notes:
Check for a gap between the module and the printer, then attach the spacer module if necessary.
Attach the NFC card.
Turn on the printer.
How to update the print server firmware via FTP (File Transfer Protocol)
How to Update Print Server Firmware Using the Web Interface