Whether you are updating a rig to a newer version, replacing a broken rig with a working copy, or switching out a default rig to a customized version, replacing references is a great way to do this.
Replacing a Reference
To replace a reference in Maya, first go to File - Reference Editor in Maya.
Next, in the Reference Editor, select the reference you want to replace
Right-click on the selected reference and go to Reference - Replace Reference
Finally browse for the file you wish to replace your reference with and hit Reference
Your reference should now be updated and the file path in the Unresolved name should be pointing to the new file path.