It's easy to fit it though- just make sure the jumper is set right (it will tell you in the manual) and then just unscrew and disconnect your old one, then do the reverse on the new one.
Then you need to enter your BIOS by pressing probably Delete just after you turn it on (repeatedly so you don't miss it) and turn the relevant drive detection onto Auto if it isn't already
Windows should see it and install the driver automatically.
Trust me, this is the easiest upgrade you could do (well, ones that involve opening up your PC anyway)