The "nut inserts" are commonly called riv-nuts or nutserts, a special tool in usually required to crimp them in place.. you can cheat it and use a bolt, and a nut. Thread the nut onto the bolt, make sure the bolt gets enough thread
engagement into the nutsert. Now hold the head of the bolt while you turn the nut to crimp the nutsert.
Photo of cheater tool
http://www.pegasusautoracing.com/Images/L/659.JPG
Another style tool similar to a rivet gun
http://gallery.mindbent.org/albums/t...0031.sized.jpg