How do you adjust the shocks on a 1980 H onda cb 650?

Spring Pre-load adjustment for rear suspension. Spring pre-load can be adjusted by rotating the cam ring at the base of the spring. Rotate it clockwise to increase pre-load or counter clockwise to decrease pre-load. Use the spanner wrench provided in the owners tool kit for the adjustment. Both cam rings must be indexed on the same notch. If you need anymore info on cb650 go to catsass site - I have a manual for it.