We had a 2000 Grand Cherokee which was towed with a Blue Ox towbar about 50,000+ miles while we had it. All you do is hookup, place the transfer case in N, put the transmission in Park and make sure the key is in the ignation switch and the steering wheel is unlocked. Then take off.
BTW, there's a photo of it, with a cover I have for sale posted in the for sale section of the forum. We have replaced the GC with a new '06 Liberty diesel, which we also tow 4 down.