I'm an introvert.
What’s one thing (one sentence) I should force myself to do in order to quit my introvert state and have the confidence of talking like a CEO should have, in any situations?
Talk to strangers everyday... anytime your in a lineup, buying something, coffee shop, etc... learn to ask great questions and tell great (short) stories. There's books on this, like Never Eat Alone by Keith Ferazzi + many others.
You don't need to quit your introvert state. Embrace it. Manage your time and energy so it works for you. I'm an introvert and find that using the Internet to connect with people makes it a lot easier and more comfortable when I meet them in person. Cuts through the barriers.
Go to an industry convention/trade show and work the floor.
Like Dan said, put yourself out there. Being an introvert doesn't mean you can't be outgoing in public settings. It just means that your preference - where you recharge your batteries - is when you're alone or in very small groups.
Just be aware of the need to strike a balance between your desire for quiet and your need to push yourself out of that comfort zone.
I'm an introvert. I've also been a CEO. And taught classes on public speaking. Introversion and talking to strangers are not mutually exclusive.
For me though, every interaction is always a race to getting them to laugh, or even just grin. Once you do that, all the tension just drains away.
Watch lots of standup comedians on YouTube. See how the speak and copy their body language.
Also, try asking real questions as soon into an interaction as possible. What do you do? What do you enjoy most about it? What do you need more of at the moment?
Suddenly in the space of 30 seconds they're telling you what their biggest pain points are. Just because you asked.
Don't just attend, but engage and participate in B2B networking events or business conferences with built in mix-n-mingle after parties.