Its very easy, after you master the technique, you may need a few attempts but it works !
View 3d Vr google videos without glasses, using only your monitor screen, just follow the steps shown on this video and you can experience the feeling provided by the cardboard VR, keep trying, you may need a few attempts before you can see the 3rd screen, for best results use fullscreen and sit one meter from the screen.
Neste video mostro como ver os videos do google cardboard VR sem os oculos, é só seguir os passos e ir tentando, depois de dominar a tecnica podem ver qualquer video utilizando a mesma tecnica.
Video subtitles English and Portugues.
Google translator used to help in the translation.