I have a Honeywell programmable thermostat that I installed about three years ago. I do not have the manual nor do I know the number of the model. It reads "Low Battery" but I do not see any way to open it up to replace the battery. What do I do ?

Find the model number if you need us to help,, honeywell has made several thousand tstats,, you might try and see if it can be removed or opened up