Alienware x51 R2 SSD upgrade

Hi,

There is no room for you to do that if you want to keep the old 2TB HDD.

If you need more information, please send me a private message with the service tag. 

I have an Alienware Area 51 R2, service tag

I wish to upgrade the existing "SAMSUNG SSD PM871 2.5 7mm 128GB", which runs the Windows 10 OS, to a "Samsung 960 EVO Series - 1TB PCIe NVMe - M.2 Internal SSD (MZ-V6E1T0BW)"

I want to know:

1. Do I use the same physical slot the original SSD sits in, or do I use a PCIe x16 slot. (I believe 1 PCIe x16 slot is in use by the NVIDIA Titan graphics card).
2. Based on the answer to #1, above, what adapter do I use to allow it all to fit?
3. If answer to #1 above is to use a PCIe x16 slot, may I still add a 2nd graphics card in the future or have I extinguished all hope of doing so by running the new SSD on a PCIe x16 slot?

Any help you can provide is deeply appreciated. I've been away from hardware for a long time and am pretty lost with the incredible hardware existing today.

Thanks,

Jim Kay