Looking to change my Xfinity internet speed

Hi, 

I have taken an Xfinity internet plan for 1000 Mbps download speed with a 2 year contract. However, with an update in my living situation, I am finding this speed much more than is needed for me, and would like to switch to a lower speed (like 200 Mbps). Is there any way I could start this process? The Xfinity app doesn't allow me to do so, and suggested I speak to a representative.