I need help!:( So.. sadly I've chose to wean my baby of my boob to a bottle (formula) due to…

I need help!:(

So.. sadly I've chose to wean my baby of my boob to a bottle (formula) due to personal reasons. Anyways. I would like to do it slowly so I can avoid mastitis and get used to it emotionally and also for the baby as well. Knowing this, I will be cutting a feeding each week and giving her a bottle. She eats 5 times a day meaning thus will takes 4-5 weeks. I just want to make sure if this is correct in what I'm suppose to do to dry up my tits?? Also the times I'm skipping a feeding don't do anything with my tit correct?

And.. I was also curious that ibe heard stories of women who go back to work so they bottle feed their kid formula during day. And the 1st and last feeding of their baby they breast feed! Is this something I could safely do to where my body can get used to it to where I can still breast feeding twice a day? How do I come about this?