A:Answer The upgrade that you purpose is probably the best investment you can do for this machine, two weakness for this particular model, Touchpad flimsy build quality and a very slow hard drive.
In order to proceed with the upgrade, make a back up of every important data, turn your PC off, then just remove the small Philips type screws located on the rear, remove the back lid (carefully, it will fill like removing back covers of old Samsung Galaxy phones, S3 or S4) exchange the HDD for the SSD, reinstall Windows and restore back up copies using your favorite method.
Warning: Before proceeding check if this procedure can damage your product warranty.