peel his top hand
After you pull the far arm towards you, you should free your wrist to where you can advance into an underhook... Try to immediately throw him by or hitting a pick from the underhook.
Aside from the double vulnerability, this is the part that makes this counter so much more effective. If done right away, you have a fantastic scoring chance with a knee pick.
While posting to the head can provide the opportunity for your opponent to hit a double, as well as an inside trip, pulling the far side arm has it's risks as well.
Gene Mills has an excellent video on youtube that shows a throw when you have the russian and you opponent pulls the far arm.
Basically, you resist the pull until he is really pulling hard. Then, you give him the arm hard. At the same time block his near ankle with your inside foot and pull hard with your inside arm while twisting your hips from the outside to the inside. He will pull your outside arm into an underhook for you and your inside arm acts like an overhook. He will go right over his own hips, since his foot is blocked, for a nice overhook/underhook throw.
yea do not post on his head. if grabbing his arm doesnt work you can also punch your hand to the floor and that might break is grip on your arm. just depends if he has a good hold or not.