There are several ways and can be done manually with photoshop.
Time consuming and tricky
https://www.youtube.co/watch?v=3tUl5Gw7e90
https://www.youtube.com/watch?v=LQ0RuWf-J1k
I use a python script and StereoPhotoMakerPro
(Open source & free) The python install is complex but well worth the investment in time.
http://stereo.jpn.org/jpn/stphmkr/google/indexe.html
Once installed it takes about 30 secs to generate the 3d.