Undo the screws holding the round tops on the shifter
And throttle, undo the 4 screws holding the cover plate to the shifter, undo the 4 screws
Holding the assembly to the hull and lift it up. Undo the cable
From the throttle and disconnect from motor. Slide the old one out and the new one in and assembly is in reverse order. Drink a beer
All the screws on mine that hold the levers to the boat up by the captain's chair were totally seized, and snapped when I tried to remove. If you encounter resistance, hit it with penetrating oil so you don't have to drill and re-tap like I did!
click the parts tab on the top of the page. you can get the numbers there. I don't know if they will have the cables or not... but if they don't, use those numbers over at SBT.