Tow driver probably said something like "disconnect the drive train." The drive train is the chain of things that make it go: the engine, transmission, driveshaft, etc.
A few tips to help you on the way:
- there's a "spider" or "u-joint" at each end of the drive shaft. It has a cap at each of its four points. Inside that cap are a whole lot of needle bearings. If the cap comes off the bearings go everywhere and it's a bear (at best) to re-assemble. Don't let the caps fall off.
- There may be a splined section in the middle of the shaft which allows the shaft to expand/contract in length. If the shaft becomes separated at the splined section due to curiosity, inattention, etc, it has to be reassembled in the right rotation. Usually (always?) that means the u-joints at the ends of the shaft are oriented the same way. Both of them aligned in the vertical plane, for example. If it's not done correctly it'll produce vibrations while driving.
- U-joints and the splined area often have grease zerks for lubrication. This is a great time to add new grease. Do it after the caps are secured into the ears of the yoke on the transmission and differential, though, or the grease will force the caps off and you'll be in the "needle bearings everywhere" situation!