I am a street rider and dont generally ride hard and I am looking into getting new springs and heavier oil. I have narrowed down the spring rate of .85 for my weight. Should I use 20 wt oil in the forks? Also wondering if I could do this job at home? What special tools would I need (I know I would need a torque wrench) or should I just get a service manual for my bike? Any advice is greatly appreciated.