1. Open your Blueair App, then delete your air purifier from your account. You will find more information here. (link to Q: How to delete a device from the App?)
2. Pair your air purifier with the Blueair App again to connect to the new Wi-Fi. Keep your new Wi-Fi network name and password handy during the pairing process. (Link to how to pair Blueair purifier to the Blueair App)
If you want to switch the Wi-Fi network for more than one Blueair air purifier, please repeat these steps for each device.