This is what I've done and I pass 100% of the time.
When you speak, only use those muscles above the adam's apple (the ones that contract when you swallow), instead of using the full range of muscles in your throat. This will give you a female resonance without having to try and raise pitch. After a while, you'll be so used to only using these muscles that it'll become second nature and you won't even have to think about it. Trust me, it works and it's sooooo simple!
Another tip...when you speak, you want it to vibrate only in the upper portion of your neck, above the adam's apple. Using those upper muscles, it will only vibrate there.
Also explained differently from someone else
"Take a few breathes naturally and relax your throat. Then take your index finger and find your Adam's apple. Once you've done that, speak without ever letting your Adam's apple drop back down to your finger. It can drop down a few times as you make deeper sounds like 'O' and 'W' but you want to try and hold the voice box above that. Practice this regularly when you're in private, specifically holding your finger on your throat (it will look weird if you do it in public), until that's where you've trained your throat muscles to speak from.
Don't over practice either. Remember, you're working out muscles. Just like any other muscle, they need practice, but they also need time to heal and recuperate."