They're hard to follow, but I think this is what you're looking for:
1. Turn off the tractor. Engine off, no lights on the dash....as in the key is completely off.
2. Lock the brake pedal down. The instructions say to press the brake pedal, but I found it easier to just lock it down while performing the procedure.
3. Hold the "Calibration" button down with your right hand, and turn the key to the "on" position with your left hand. It's challenging, but do-able. After about two seconds (one Mississippi, two Mississippi), release the calibration button, and the dash lights should cycle through the sequence (N-L-N-M-N-H-N-L-N-M-N-H) and then stop with the N (neutral) light illuminated on the dash. If the lights don't flash, turn the key off and try it again.
4. To set the upper pedal limit, make sure both HST pedals (Forward and Reverse) are in the "Up" position, as in you're not touching them, depressing them, or have your foot remotely close to them.
5. Press the "No Stall / Speed Limit" rocker switch to the "No Stall" position.
6. Press the "Cruise Control" button once, just like you would if you were setting the cruise control.
7. The N (neutral) light should go off, and the Calibration light should be on.
8. To set the lower pedal limit, press the "No Stall / Speed Limit" rocker switch to the "Speed Limit" position. Recall that it should already be at the "No Stall" position. You're switching it directly from the "No Stall" position to the "Speed Limit" position.
9. Depress both HST pedals (forward and reverse) to the floor at the same time. You may have to turn sideways in the seat and use your left foot to do this, but however you do it, you have to push both pedals to the floor at the same time. Wish I'd figured this out the first time...stupid me or stupid instructions...whatever.
10. Press the "Cruise Control" rocker switch once, just like you would if you were setting the cruise control.
11. The "Calibration" light should go off, and the N (neutral) light should come back on.
12. Now, and only now, can you release both HST pedals.
13. Turn the key off to exit the calibration mode.
Like I said above, I don't believe it's necessary to release the brake pedal at any time during the calibration procedure. You can test the calibration by turning on the tractor and putting it in Low (highly advised), and then slowly moving. You'll know immediately if you got the procedure wrong because the tractor will jerk, buck, etc when you push the HST pedals. Don't ask how I know.
Hope this helps!