I went into the Blaine WA enrollment center on Monday to update Nexus for my new US passport. The US update was no problem (I'd already done it online) but for the Canadian CBSA update I was told to email a photo of my Nexus and new passport to a very long "*.gc.ca" email address.
I commented that I thought the updating procedure was to come to the enrollment center and her response was "there's no one here today that can do the update".

After emailing the info to CBSA, they replied in just a few hours that the updates were done.

nrg