I have a 1 year old Toro SS 4235 With the 20HP Kaw motor. I am mechanical and I a DIY guy. I want to change my filters and fluid but apparently this model dosent have external spin off filters they are internal. Any one have diagrams or a "how to" thread on these mowers? I cant find ANYTHING online. Also what kind of fluid will I use? I have a very hilly 2 acers and I want to swap the fluid regularly.