Switching an Alienware HDD to SSD from another Alienware

Hello,

    I was curious about how to switch a HDD to SSD that was previously in another computer. 

So I have last years Alienware Alpha (i7 1tb SSD and upgraded to 16gb RAM) I have many files, programs and steam games on there about 650gb+ worth. Now with my work I need to upgrade my system, so I was able to get a great deal on the Alienware x51 R3 with the i7 and HDD. What I would like to do is put the 1tb SSD in the x51 R3 so I can have all my files and then just buy a small 250gb SSD and put it in the Alpha so I can pass down my old set up to my nephew. They both run windows 10 64-bit 

i wasn't sure if it was as easy as just removing the SSD, put it into a 2.5" to 3.5" converter and that's it, or if their are other precautions I need to take to make sure my files and everything are kept in place. I edit photos and videos for a living so I am a novice when it comes to computer hardware and builds, if you have any suggestions, please put them in layman's terms, I am not very good when it comes to stuff like this.

Thanks!

-Rob