SkyWatcher EQ5 mount declination query

[barrett.ap]

Configuring the polarscope to the mount:- an early instruction says 'set the declination to 0 degrees and lock the clutch'. How can I do this when the silver cirlce marked in degrees that surrounds the counterweight bar is moveable? The mount was recently acquired from a late friend and had only a motorized RA. I now have the full GoTo upgrade on it.