First you'll need to jack the rear of the machine up and put it on jack stands. Next you'll want to lock the thumb latches in the neutral lock position to remove the tension from the drive belts. You can also remove the belt shield and deck belt if it makes it easier to access the axle mounting bolts from the front. The axle mounting plates should be painted black originally which should make locating them a little easier. The axle plates are mounted behind the wheels and held in place by two bolts. The lower bolt well need to be removed and relocated when you raise/lower the axle. The Top bolt mounts to the lower part of the tak support and only needs to be loosened to allow the axle to pivot. Once you've relocated the axle you'll need to re-adjust the drive linkages.
For the drive linkage adjustment on this model you'll want to release the drive levers from the neutral lock position. Then make sure the pin that holds the linkage to the drive lever has about 1/8" to 1/4" gap before it bottoms out in the thumb latch. Youll also want to make sure the drive levers dont touch the handlebar grip. You want about 1/8 gap there. This is one of those adjustments where the manual is nice. Give me a call if you have any questions on it at 800-667-5296.