Thank you guys! The main point for my question is whether it can be Do-It-Yourself or I have to go to dealership to do it. I searched before I sent out my post. I saw cduluk's post up the top and I found that very useful however he's describing what need to be done AFTER battery is disconnected (as SW03ES mentioned) but not addressing whether we can change our own battery without any adverse effects.
I remember seeing something like you have to go to the dealership to change the battery because the car memory stores information related to the communication to the hybrid battery (something like that) ...
Thanks to katzjamr for confirming me that it can be DIY and we just need to reset the windows/ stereo/ NAV memories.