If you have a torque wrench, good quality torx bits, and a jack, you can easily do this yourself. You will spend more time sitting at stoplights on the way to the dealer than it will take to get the tube height corrected.
Jack up bike so the front wheel is just ready to leave contact with the ground. Secure bike with tie-down straps. Spray WD-40 on tubes above and below trees to lubricate and keep from scratching. Loosen upper and lower pinch bolts. Adjust tube position (height). You may need to slightly raise or lower jack to aid in tube positioning. Tighten pinch bolts to 30-35ft-lbs (41-48 Nm).