I have a 2010 Fortuner's key fob that is now very weak. Sometimes it will lock and unlock, sometimes it doesn't even though the LED light from the key fob will light up.

Since the battery would be 11 years old, I thought of just replacing the battery and see if it will perform better. Can I replace the battery by myself or should I bring it to Toyota dealership?

Because my worry is that replacing the battery will require reprogramming of the alarm system that only the Toyota dealer can do.