The best way to keep a skunk from spraying in a live trap is to cover the trap with a blanket, towel, or canvas before setting it. The cover will keep the animal calm when you approach it to move it, provided that you do so quietly. You can then move the skunk by placing the skunk while in the trap into your vehicle's trunk or back of pickup truck. Keep the towel, canvas or blanket on the trap. Once you arrive at a park, wildlife management area, etc., place the trap on the ground, keep the towel or blanket over the trap, open the door, and leave. Return later to retrieve your blanket or towel and live-trap. That is the best way that I know of to trap and move a skunk without being sprayed.
Hope this helps!