Here are some photos of the stepper arms these guys do most of the work.

STEP 1 first thing i do is blow the unit out with compressed air or attack it with a dry paint brush to remove any unwanted   
            dust  bugs etc.

STEP 2 any leftover grease hard dirt etc i clean with a toothbrush dipped in metho preferably not your own especially around
            the pivot point

The second photo shows the build up grease that blowing and paint brushing didn't remove third show what a quick hit with motho on a toothbrush can remove