[NAME]  - You can't do anything without a mouse, monitor, keyboard connected. You don't have to remove the NVME SSD to change BIOS from RAID to AHCI. Boot from the HDD normally and follow steps 1-8. And yes, open the CMD prompt window, run as administrator, in both steps 1 and 6. You don't power PC off while doing steps1-8. You type in the first command into the CMD window and press Enter. When it's done, just close the CMD window and reboot. When you see the Dell splash screen, start tapping F2 to enter BIOS. Change SATA mode to AHCI and save the change. Now exit setup and PC will reboot automatically. Back at the desktop, and open a new CMD window, run as administrator, and type in the second command and press Enter. Then just reboot again to finish. After you make change to AHCI, you should back up the HDD on external media again because the images you previously made are with RAID enabled, so they won't boot the PC after you change BIOS to AHCI. Once you've backed up again, do the cloning with whichever software you want and be sure to reside the C: partition when it's copied over to the SSD. The exact size for C partition will depend on how much space the other partitions need (don't resize any of them) up to the limit of the NVME drive, which will likely be less than 1T total usable space. You don't disconnect the HDD to reformat it for storage. After you clone the HDD onto the new SSD, including adjusting the C: partition size so everything fits on the 1T SSD, just reboot via the F12 menu to make sure the image on the SSD boots the PC. This is the critical step. If PC doesn't boot and run normally from the SSD via the F12 menu, don't go any further until you fix the problem(s).  Once it boots/runs normally from the SSD, open Windows Disk Management without rebooting  Select the HDD from the list of drives in Disk Management and initialize it. Once it's initialized, just restart the PC normally. It should boot directly from the SSD, without having to use the F12 menu. Windows will assign drive letter D to HDD, and it will be completely empty, ready to store files.
I have XPS 8930 desktop which showed boot failure after soft ware update. I tried change boot order, legacy or UEFI etc but nothing seems to change the message of boot failure. Even call Dell support and referred me to software department and they couldn't resolve the issue and refund the money I paid to me. Refer me hard ware department to change the DVD Drive which I replaced it myself and still not solve the issue. Now I was referred to hardware department for another service and awaiting for it. Meanwhile, any one has similar experience and can share how they fix it please. I cannot go to recovery window and I don't think I backed up my PC to USB image or CD/DVD because these are usually useless from my experience.   
XPS 8930, boot failure