The problem you are facing is the you cannot erase/delete/format the C drive and the way to put the Windows on to the SSD would be to remove the two drives by diconnecting them and then loading Windows on the SSD. You can create a mirror image from you current Windows install to be used later to recover the settings. Then when you start the Pc up you will have the option of picking the Windows install to load up and recover the settings from the mirror image.
One way to delete the C drive is to use Linux. You download Linux to a bootable usb stick. Disconnect the SSD, then with the stick in the usb slot start the computer up with the two drives in raid conncted and when you have the option to install Linux say yes and you can choose to load Linux onto the C drive(not the SSD C drive) and once it starts it says that the Windows install will be over writen and you say yes but before it finishes you stop it and the Windows install will be corrupted and you can now delete/format/divide up that partition.
One thing you may now encounter is that the Windows install on the SSD will not know where anything is on the other partitions and I don't know if the mirror reload will help with that. It's not perfect but it may take some work to finally straighten it all out.