Pentax-kr change Split focus screen

It is a quite simple if you know how to change it. I did not success in the first a few tries. So I decide to make a video about it. The key point here is to put the rough side of the focusing screen facing up(the viewfinder) and the smooth side of the screen facing the mirror. The tag(ear)’s position does not matter, specially if you bought a non-pentax screen.