This is a very simple transition from Side Control to Mount.  This is the first transition taught to white belts and focuses on sound basics (maintaining base, getting the underhook and entering the knee at the armpit).

Make sure that you emphasize this is not a fast technique.  Take your time, dominate your opponent drive that knee into the armpit.  Do not, and I repeat do not try and cut the corner with your foot near the hip bone.  This will lead to you being put into Half Guard or Quarter Guard.  

Notice at the beginning of this move that I place my knee on the near side hip bone.  Do not try to advance the knee to far as it will push your base to far over your opponent.  You're looking to draw that hand to the top of your knee before you commit to the pass.