With an UNSIGNED lab result:
Be sure that a provider is assigned to the result.
Click the Actions tab on the right hand side, select Change Patient.
From there you can search through your EHR to find the patient to whom you would like to assign the result.
Once you have located the patient, select the blue Assign button.
Please note that any diagnoses that were added to the result will be cleared, to prevent erroneous diagnoses in patient's charts.