Hey there, Teong.
Sure, as every other laptop there is out there, this one should be upgradeable. Although I'd recommend that you check beforehand if this voids the warranty of the laptop if you decide to do it yourself. Other than that you should make sure what type of drive it uses before you get a new one, by checking the specifications or by contacting the manufacturer's customer support to ask for further info on that.
Hope that helps.
Boogieman_WD