^^^^^^what he said^^^^^^ If you turn the key to on you will put a drain on the battery. One step foreword will unlock the wheel but not turn the power on. As noted you will need to pull the driveshaft. You can leave it in place but there is a speed limit and distance limit for towing with the drive line intact. I would bet the owners manual is still in the truck and it should give you the towing restrictions.
Don
Or you could use a tow dolly and load the tuck with the rear tires on the dolly. You would need to use a wheel lock to hold the steering wheel in the straight froward position. It is not a good idea or legal to depend on the wheel lock to hold it in position.