Hi, how can I get configuration mode in Garmin g500?

Found this on the web:

To enter into Configuration Mode for the G500/G600 system, verify that the GDU 620 is off and an
Installer Unlock Card is inserted in the SD card slot of the GDU 620. Apply power to the GDU 620 while
holding the ENT key. Release the ENT key when “INITIALIZING SYSTEM” appears in the upper left
corner of the display.