Before adjusting the AccuTrigger, ensure that: the safety is on, the magazine is removed, there is no live ammunition in the chamber, and the bolt is locked open.
Since the stock does not have to be removed to adjust the AccuTrigger, insert the supplied tool into the hole in the rear of the trigger guard and rotate gently until it engages the trigger return spring (see detailed steps on pages 13 and 14 in the INSTRUCTION MANUAL).