I had a similar problem where I wanted to install my OS onto a hybrid drive from my HDD. Basically, I would boot from the CD or USB that you have your OS on and press custom instead of upgrade. If you click the drive, there should be some options for you to do such as format this drive, partition it etc... Click the format or delete one on your HDD and install it on your SSD. If you've upgraded W10 from W7, I recon you should just install windows 10 on a USB, make sure you have your product key if you do or else you'll have to buy a new one.
So basically, I wouldn't recommend that method and as far as I know, you cannot do so.