Imo the most important part is consistent training. Every day, only a few minutes in the beginning.
Simply reading a book for example.
It takes months.
Never overstrain your voice, just stop then. And drink some water from time to time to keep the throat moist.
To avoid errors some people consult a voice trainer in the beginning.
Some people have used different available training packs, with hints, but its necessary to train nonetheless.
There are a few different techniques. Falsetto, etc.
I read a hint of someone stating that she trained a higher register for a few days and it felt like a click and she was there.
I found that helpful, the falsetto method goes much higher.
Its simply raising the voice a bit and trying to reduce resonance in the chest area, moving the voice to the head area.
It can be checked in the beginning by laying a hand on the chest from time to time, if there are vibrations there it should be felt.
There is a software called overtone analyzer. Its free in its basic function.
For target levels and hints you might have a look at
nyspeechandvoicelab dot net/transgender/voice-feminization
The software is only necessary from time to time imo.
Target levels should be only a guide, having a few deep undertones in females sounds sexy.
Another good idea is to record and listen afterwards, less and less necessary with some practise.
Females have much more intonation, voice going up and down much more... within words and at the end of a sentence....
they have a softer and a bit "breathy" voice...
and females use more indirect language... like would you....
I'd say just take your time... and practise... it really takes time...
but many others have succeeded, you can do it, too

hugs