You can also do a file open then single click on the drawing you want to change references. Next press the References button and double click the file under "New pathname". Then browse to the model you want as the new reference and either double click it or single click it and press the open button. You should return to Edit Referenced File Locations dialog. Now press the OK button. Finally press the Open button from the Open dialog.
The drawing should open with the new model you selected as the reference.