Ok, good start. Why do you think they are not producing correctly?
I'm certainly not suggesting that you are not correct. But, assuming something and having evidence are two different things.
Is the scrap rate way too high for that particular process?
Are there a lot of customer complaints?
Are there a lot of rework/returns of products?
And of those three, are they
really high and can be easily lowered? I'm just encouraging you to take some time and understand the process. Essentially what Steelmaiden suggested to you. Talk with everyone and understand why they are doing what they do. There may be good reasons for it.
Then once you have an understanding, then you can possible suggest some improvements. Those improvements will probably make more sense and be better received, as the employees recognize that you first took time to understand what they do.