BMW Repair: BMW E46 key fob, bmw e46, replaceable batteries

Question
hello, i own a bmw compact 318ti 51 reg.the alarm, key fob has stopped operating my alarm and central locking. i have tried to open the key fob but it doesn't seem like opening without breaking, can it be opened to replace batteries, does it take batteries? or does it need reprograming? many thanks  

Answer
Hassan, E46 was never offered in a 318ti in the U.S. What year is your car and what does your key fob look like? Older ones (slightly square in shape) with the LED have replaceable batteries in the back. 2001 and newer keys (with BMW Colored logo) dont have replaceable batteries. What is 51 reg. the alarm?
-Evan