How to take front cover of bryant (non-programmable) thermostat

Hi, I have this (Builders Non-Programmable Thermostat) from bryant and i try to replace with programmable one. Some how i have trouble to take out the current one front cover so i can replace with the new one. Does any one has this kind of thermostat before. I would be appreciated for your help.
Here is the link for the model i have:
The last one on the page.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Site Timeline is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.