Go into the Tzumi SmartHome app.

On the Home tab, tap the three dots opposite All Devices.

Select Device Management.

Select your device, the tap Remove Device.

Alternatively, you can press and hold on the device on the list to remove and  then remove the device.

Start the connection process anew, using your new Wi-Fi credentials.

Double check to make sure the Wi-Fi credentials you are entering are correct, as the App will not inform you if incorrect credentials are entered.

It will proceed to try to pair, but in the end will not connect.