If you want to move it from hard disk, system image or cloning would be your options:
Choose system image if the SSD is equal in size or larger than hard disk:
- How to: Create a system image in Windows 10
- How to restore a Windows 10 system image to an existing or larger storage device
Choose cloning if its not:
https://www.groovypost.com/howto/clone-move-windows-10-data-larger-ssd-disk-drive/
OR
You can remove the hard disk, reinstall Windows 10 directly to SSD, reattach the hard drive and format it.
Step 1: How to download official Windows 10 ISO files
Step 2: