Thanks for the good tips.
A little more info-- His first serve is a real power serve. It has some good slice/movement on it and can be very difficult to return whether down the T or out wide. On his second serve, he hits it in at a very high percentage, but it is a very low powered serve with a slicing spin. He definitely does not swing as nearly as hard at the ball, as it is easy to tell he is going to hit it softly even from the toss as he kind of pampers the ball over the net.
If you want him to actually practice his confidence for a second serve, ive found that playing best out of 5 tie breaks with a partner, where no faults are permitted.
By this i mean if you have your first serve, and fault, the point is lost.
It helped me greatly to get my second serve confidence higher. I was able to do a kick serve for a first serve, but not my second, as i decelerated my swing. Now its fixed
Check out the articles and vids that Will has posted on the kick serve on his site:
http://www.fuzzyyellowballs.com/kick_serve_step_1.php
http://www.fuzzyyellowballs.com/index.php?col=7514590