OK..>Win 10 Home.
You do not need the license key for a reinstall in the same system.
You're just putting it on a different drive. No problem.
Obtain a USB flash drive of at least 5GB. If you have one, make sure there is nothing on it you want to keep.
Go here, downlaod this tool to create your own Win 10 install.
https://www.microsoft.com/en-us/software-download/windows10
Read and do this, to link your OS license to your MS account (probably not needed in this instance, but good to have)
https://support.microsoft.com/en-us/help/20530/windows-10-reactivating-after-hardware-change
http://www.tomshardware.com/forum/id-3164428/windows-build-1607-activation.html
Now, the install....
Disconnect ALL drives except for the new SSD.
Boot from the flash drive you made, and install on that SSD.
When it asks for the license key, at the bottom of that window is a link for "I don't have a product ID"
Click that, and proceed.
When the system goes online later, it will activate itself.