I combi fed my first.
I'd caution first about doing it if breastfeeding is going well. DH can do loads of things other than feeding that can help, including doing bath time, feeding solid food when weaning, taking over household chores, having afternoon cuddles to let you nap.
Then giving a bottle a day usually creates more work than reducing it.
I'd also recommend not doing formula before bed until you've got them used to the bottle in the day. My son has CMPA and he'd throw up the special formula as well. Having that before bed wouldn't be a good idea.
As for how to do it. Introduce an oz in the day sometime. See how they do with the bottle first. Pick one bottle and stick with it. FWIW my son went between bottle and breast with no issue. My daughter flatly refused bottles and dummies. Hated them. They were introduced in the same way at same time.
Until baby is happy with the bottle / formula and you've settled on when you'll do a bottle, express the feed you're missing. Once you're happy it will work for you, you can stop expressing and your supply will regulate. Once you're past 6 weeks your supply will regulate up and down quite easily for one or two feeds. If you want to do 2 feeds a day, alternate those with a breastfeed. For example I did;
7am - breast
10am - bottle
1pm - breast
3pm - bottle
7pm and overnight breast.
For me personally I preferred EBF as it was much much easier. Once baby had settled into a routine at around 3 months it got really easy. Once they start weaning and dropping feeds it gets even easier still.