Installed wifi booster, but what do i do with old wifi id

Whichever you prefer. When I attached my boost I left the old wireless networks as-is on my Telus router. I have some devices close to it that are fine. I did connect a number of other devices to the Boost but I didn't delete the old network settings. For me the devices typically just connect to the Boost instead of the original network. If for whatever reason the Boost isn't working, they'll just reconnect to the original network as a backup.