If you can only make remote/configuration changes, I would first check the Meraki config. There you might be able to block traffic from the WAN IP of the Pep going to the WAN2 of the Meraki and back to the Pep again, so making sure the WAN Health Status PING packets from the Pep (SRC IP = WAN of Pep) are no longer answered by the Pep itself.
For physical changes, I also suggest looking at “drop in” functionalities of the Pep: https://forum.peplink.com/t/what-is-drop-in-mode/