Andy & Julia...
The basics are these:
1. This will take time. Six months seems to be a typical time frame
2. Initially you have to do this is short bursts or you will strain your voice
3. There is no substitute for practice
4. The BIG killer topic is
resonance. Men resonate in their chest and you need to lose that.
5. Intonation is vitally important. After resonance it is next...
6. Pitch helps, but anything over 170Hz will do. 220Hz is the ideal
Falsetto will help increase your vocal range and that is important but no women talks in falsetto so it is not the answer. To move resonance out of your chest, try adjusting your Adam's Apple (AA) by lifting it. Put your fingers on it and swallow and you will feel your AA move up. You need to keep it up. Try forcing your tongue forward and down and see if that moves your AA. Keep moving your tongue around until your AA moves up then practice keeping it there. This will change the properties of your airways (and eliminate the need for a trachael shave if you are lucky). The trick is to keep that AA up when talking.
Here endth the first lesson....