vw4758

I have purchased "Iron Warrior T72-Tank Command" and am having trouble figuring out how to target an enemy and how to determine the range to a target and then how to transfer that range to the main gun to fire. I need info. for the three tank models, T34, T55 and T72. I also don't understand what the different scales are used for when your in the gunners position for the T72, T55 and T34 tanks. I hope someone can help me with these problems and I thank you a head of time.