OK, done a little more research, and.....
1) You need an 8gb Usb drive or smaller. Too big, and it may not recognize it, if it still doesn't work, try a different USB drive.
2) Format the USB drive to FAT32 in windows or Mac and name the USB drive something easy, like, "Nissan Titan"
3) Create a folder inside the "Nissan Titan" USB drive root folder, and name it "myPOIs", inside of that folder, create a folder and name it "myPOIwarnings".
4) Open Excel and start a new spreadsheet. The first column (A1) is Longitude, Second column (B1) is Latitude, third column (C1) is name, and forth column (D1) is address and/or phone number. Populate the spreadsheet with your pertinent info and save it as a .csv file to your desktop for the moment.
5) if the .cvs file is something like a destination you might go to, like "Mark's house, David's house, John's house, Paul's house....." save it to the USB drive in the folder "myPOIs". If the .cvs file is something like an area your not really familiar with driving, like from Tomball, TX to Pascagoula, MS and you might stop for gas, food or something 'off the beaten path', things like "school zones, speed cameras, red light cameras, known speed traps...." are handy to know, put it in the folder "myPOIwarnings".
6) insert the USB drive into the trucks USB port, and the radio should ask if you want to update.
It looks like it will delete only the info that YOU added, not gas stations, restaurants and hotels that NissanConnect provides.....just "Mark's house, David's house, John's house, Paul's house...".
I think you can download the info for "Mark's house, David's house, John's house, Paul's house..." from Google Maps by clicking a few settings and it will show you the Longitude and Latitude and give you the address.
I think the "myPOIwarnings" pop up a screen on the nav that warns you of hazards,
I have just downloaded the Garmin file "safety_camera_us_canada.gpi" file and I'm fixing to convert it to .csv file......