IFIXIT doesn't currently have a repair guide for this model. It appears someone has started the guide but didn't get a chance to finish it {how about helping us out}. It's people like you that make IFIXIT what it is.
As to the tools you'll need looking at the other Acer guides it appears you'll only need a Phillips #00 Screwdriver. But until someone documents things you might get a surprise once you get inside. You might want to get the IFIXIT tool kit with the plastic sponger tools.
As far as the HD its' self, looking at a few parts suppliers you'll need a 2.5" 9.5 mm high SATA II HD.