What modifications are needed to flat tow a 2016 f-150 2wd?

Drive line disconnect, or just unbolt it from the differential and tie it up out of the way.

In other words, remove the driveshaft and put it in the bed. Hope that helps! Jim

Nope can't do that or the transmission fluid will run out of the tail shaft housing, the drive line must remain in place, make sure you mark the shaft and flange so it goes right back the way it came off.