At the top of the laptop you will see two switches, like in image one and two.
Pull the switches outwards with your thumb, towards the unlocked lock.
Once both switches are pulled, the battery should pop out.
Now you are ready to insert your new battery.
Unscrew four 4mm JIS #0 screws.
After you have the screws out apply pressure with your thumb and slide the hard drive to the left.
When the hard drive is completely left gently pull up on the right corner.