You can reach up under the dash and remove the old quadrant. I didn't remove anything dashboard wise to replace my quadrant. I think it's a bit more of a PITA than 84LX89GT though. The quadrant is up under the dash above the gas pedal. The big part comes out real easy, it's the small back piece thats the PITA, you have to pry the spring off the end of the spindle thing it rides on and mess with the pedal in order to remove it. Alot of people just smash the plastic into pieces to get it out
usually after messing with it for awhile (good therapy). Good luck, though IMO the Summit guys aren't really all that knowledgeable most of the time. You don't need a new quadrant or cable unless there's something wrong with the original. If you do keep the factory quadrant it has to be "reset" with a new clutch though, just so you know.