Hey there, MrMarksH.
First you should backup any important data which you might have, just to be on the safe side. Basically AHCI is included in RAID mode so you shouldn't have any issues switching to AHCI before you start anything else. If you are having issues booting after you switch the SATA controller's mode to AHCI, you could take a look at the solution from this thread:
http://www.tomshardware.co.uk/answers/id-2795928/switch-ide-ahci-windows.html
But basically you've gotten the hang of it.
1. Connect your SSD.
2. Clone your C: drive
3. Turn off the computer, disconnect the HDD and go to your BIOS to make sure that the SSD has been selected as the first booting device from the boot priority menu and to change the SATA mode to...