I need to change the rear spring on my 2018 TX300 and I'm a little confused on the correct size for my bike. Based on my weight, Racetech Calculator says a 5.2 is needed. When I go to Enduro Engineering, they say its "5.2 260mm Straight Rate Shock Spring White". AOMC has it at "Enduro Engineering 250mm WP Shock Spring (White) KTM/Husqvarna 16-18". Which is correct for a 2018 TX300, 260mm, or 250mm? Also, does anyone know of a good "How To" video on changing the spring? Appreciate any help ensuring I get the right one to start.