Select "Edit Chimes"
Your sensor list will be displayed. Find the sensor you wish to change and select the "Edit Pencil" icon. As a demonstration, I'm going to adjust the chime for my "Front Door"...
Select the "Dropdown" for the "Chime Type"
Select a sound and press "Play" to hear a sample
Once you have decided on a sound, finish by selecting "Save"
You have successfully changed your chime on your IQ panel!