Thommo - Hello. This new thread is in response to your inquiry on Alco1000's post about sound improvement. I have removed my sideframes on my S4. From the pictures you posted, the trucks look identical to the S2. At the ends of each truck, there is a molded upside down U plastic extension, that snaps over a molded cam ramp on the main body of the truck. Take small, thin screwdriver, approach from the bottom of the truck, and gently pry the plastic U away from the axle. Only need about 1/16 inch to release. The axles and gears on my trucks were snap fitted into the body of the truck. The wire you need to reattach joins a very small power strip. Best to remove from truck to re-solder. Good luck. Dave