You install it just like you install it onto HDD.
BIOS -> Drive Boot Order -> Put SSD as a First Boot Device.
Then insert disc with the OS in your disc drive and reboot, and proceed with installation. You can also install from a flash dongle.
You can't just copy your OS from an HDD to SSD, just as you can't copy it from one HDD to another HDD. You'll have to make a fresh install.
Read
this for more information on "why you can't just copy OS".