Bobby how do I start downswing with lower body separated from upper body seems to me I am doing all three at once lower upper and arms how do I segregate all three?

Segregating the three is not what you should be trying to do. As a general rule, the lower body, powered by the ground forces should start the downswing sequence. The upper body should follow and rotate. Once I know what your natural tendencies are, I can recommend your needed thoughts to get into the right sequencing.