In this video I install an mSATA SSD in my Intel NUC. This NUC will have two SSDs. One will have Windows. The other will have Ubuntu.
Ultimate Intel NUC Playlist: https://www.youtube.com/playlist?list=PLErU2HjQZ_ZNqgp0yXEWkhTdFm1ZkAt7h
Samsung 860 EVO mSATA: https://amzn.to/2t1ykzR (Amazon Affiliate