If your ssd will hold the contents of your os drive, you can clone the hdd to the ssd. It is very simple.
Intel and Samsung have free clone utilities for their ssd's.
Otherwise, a clean install should be no problem. Do not leave your hdd attached during the process, or windows will allocate a hidden recovery partition which complicates a later hard drive removal or reformat.
You can reattach the hard drive later, and all your files will be accessible.
Then, you can delete the old windows files.
Your apps will need to be reinstalled because you will have an empty registry on the ssd.