The torque covers on AT-2000/3000/4000/4500 electric screwdrivers has a two-piece design to provide better prevention against tampering of the torque setting.
To remove the torque cover, first loosen the set screw located at the end of the black cover with included allen key and remove the entire cover by turning it counterclockwise. Remove the Philips screw on the cover and push out the inner piece from the back end. Reinstall the remaining cover, and now you will have access to change the torque setting.
For more information about CHP assembly tool or any other products from American Hakko, visit www.hakkousa.com or contact us a 1-800-88-HAKKO(42556).