I am not sure what you would need to do to move into Penetration testing. my understanding is that this is a highly specialized are where some the skills needed are very different. You need technical knowledge and abilities on how systems work and how they can be compromised, to some extent it is legal hacking.
I think that your technical knowledge and skills and abilities in that area would be more significant in moving across to this type of testing.
A couple of ways to find out what skill you need:
1. Locate companies that specialize in this testing and:
a: Speak to someone at the company to find the information you are looking for
b: Look at their job openings to identify the types of skills that they look for.