Sensor battery replacement

I’m looking to get the alarm system but it states the sensor battery lasts for 2 years. Can the batteries be easily replaced or would I need to purchase new sensors every 2 years?

The motion sensor battery is replaceable. You just slide the back battery compartment cover up. It uses a CR123A lithium ion battery
I would guess the entry sensors use the same battery also.

@jd164 is correct. Both sensors use the same batteries and they are easy to replace. My system is over 2 years old and I still haven’t needed to replace the batteries, even on my gararge door which operates 3-4 times a day.