You can assign a person or group or change the person/group already assigned to the customer accounts currently displayed in the Collections Search Results window. To bulk assign customer accounts:
Right-click anywhere in the Collections Search Results window and select Bulk Operations > Bulk Assign Account. This displays the Bulk Assign Account window.

Select the person or group you want to assign from the drop-down list.
Click Save to assign the selected person/group to the customer accounts currently displayed in the Collections Search Results window. This displays the Bulk Operation Status window indicating the bulk operation completed successfully.
Click OK. This updates the Assigned To column in the Collections Search Results window with the new assignment.