Its just one screw that holds it in place, but a bit of maneuvering needs to be done in order to get it located. its not hard, but really you will need to remove the transmission, and to make the job easiest remove the top cover of the machine to make for easy replacement of the transmission. That pedal unit includes a metal swivel/lever which fits in between to gears on the back axle. When the lever is pressed to neutral that lever separates those two gears. When in the drive position the spring loaded gears are allowed to join. Again I'm probably too late to help, but if you look at a previous answer I made to a person with transmission probs, instructions for transmission and top cover removal are there in detail.
GJ, June 2011
