When choosing a replacement hard drive, make sure you are choosing one which is 7mm in height, and not the more traditional 9.5mm laptop drive, as it will not fit given the limited space inside of the laptop.

Using a PH0 sized screw driver, carefully remove the 4mm screw from the bottom cover.

Using the plastic opening tool carefully pry open the bottom cover

Slide the bottom cover towards you and remove it from the laptop base. Put the cover aside.