Don't invest in sales training! If you try teaching sales training to a guy who has limiting beliefs and whose mindset is already off, you're done before you got started.
The first thing you need to do is adjust your mindset and limit belief training. Once you get somebody to see things in a different way, their limited beliefs will start to change.
How do you shift the mind? You can do it with surveys, conversations; a couple good questions can tell you what that person is thinking.
We change every day based on what we hear on the news, in the media, what your wife says, what your dog does. We can change once we see something that allows us to see it through a different set of eyes.
I challenge you to look at your team and ask yourself, where is their mind? And, where does their mind need to go?