This video provides another option going from the Mount position to Side Control. There are many reasons that you would make this transition. Sometimes your opponent is to large and your knees dont touch the floor or maybe it's getting later into the match and you are down on points and your opponent is interested in stalling. Regardless of what the reasons for the transition is, it is important to stay in a dominate position.
Notice when I do this move that I transfer my weight forward and put a lot of pressure on my opponents face. This is important to cut off his hip movement and to give yourself the space to hook the foot at the hip. When hooking that foot at the hip make sure the top of your foot is plastered to your opponents hip.
Also when I make the final part of this transition you notice that I dont remove my knee from the hip until my hand is ready to take over control on the floor. If you move your knee to the floor and then try to move your hand you will find that your opponent has a small window to recompose guard...dont give them that opportunity!