Release the parking brake and place the transmission in Neutral. It is best to tow the van with its drive wheels off the ground. If the drive wheels are on the ground, the transmission and differential must operate properly. If they do not, place a dolly under the wheels or disconnect the driveshaft.
If the van is being towed on its front wheels, the steering wheel should be clamped in a straight ahead position by a steering wheel clamping device, such as that provided by a towing service or towing system manufacturer. It is not advisable to use the steering column lock to hold the wheels in the straight ahead position.
Whenever possible, follow the vehicle manufacturer's recommendations for maximum towing speed (35 mph) and distance (50 miles).