What are the battery requirements and how do I replace the batteries in the e7w thermostat?

The e7w requires four AA alkaline batteries (1.5VDC each) that provide 6VDC total power. Insert the batteries into the battery compartment, matching the '+' terminals on the batteries to the '+' symbols in the compartment. When the low battery alarm displays on the screen, replace all four batteries. Use alkaline batteries only and dispose of used batteries according to the WEEE Directive 2012/19/EC instructions. (Page 28-29)