Just tow it with your bill of sale- but be safe and smart about it. Make sure you take an extra copy of your paid in full invoice and have the GL rep sign and date your copy so you have it.
If you are towing with an MV, just make sure you have spare bulbs, hook it up and go. If you have never hooked up to your trailer plug before inspect it, make sure it is in good shape, and verify it has voltage at the proper terminals. A light coat of grease around the outside will help stubborn plugs go in.
If not towing with an MV get some magnetic lights. HF ones are cheap and don't stick well, and are often miswired, but are cheap. Northern Tool sells a great set that works well and lasts- if you plan to use them more than once buy the good Northern Tool set that comes in the black plastic case, but replace that stupid 4-round plug with whatever is on your tow vehicle. The Northern lighst stay on with the magnets, if you get the HF ones zip tie them down the magnets suck.
Take a spare tire (unless your tow vehicle spare fits), jack that works with it, proper lug wrench, some 1.5 foot length chain legs with adjustable links to extend your safety chains if needed.
Jack it up at GL and spin each wheel and make sure that the wheel bearings feel smooth. Grab the top of the wheel and pull/push and make sure that there is no play in the wheel bearings.
Verify your lugnuts are tight.
After you leave the lot, go slow the first few miles, get out and feel the wheel bearings. A few slow miles shouldn't have any noticable heat. If they pass that test, go about 5-10 at speed and repeat- slightly warm is OK, hot means problems.
Know the civilian part numbers for the wheel bearings in case you have to stop and buy some at a mminimum- even better have a set on hand.