So,if I buy a SSD and install on it Windows 8.1 but I already have installed Windows 8.1 in my current HDD,how could I delete the Windows 8.1 that my HDD has installed(including all my personal files) in order to use all that 500GB just for storage,I mean,do I have to use some kind of program,or is there any windows feature that will delete the HDD's Windows 8.1(and my personal files)completely,and If there is a way could you please explain to me how?
P.S:I know that is a very simple thing to do but I am too nervous to try things that I've never done before,and sorry for the inconvenience guys.
Thanks.

P.S:I know that is a very simple thing to do but I am too nervous to try things that I've never done before,and sorry for the inconvenience guys.
Thanks.