I had the surgery done on both of my big toes, both sides.
Let me preface with this, the surgery is very short, done with local anesthesia, mostly painless, and very cool to watch. The recovery time is short (I think it was 3 days until I was able to play soccer again).
Now for the gory details. To start, they need to numb up your toe. The nerves they need to numb on the underside of your foot on either side of your tone bone. For reasons, they can’t just do a short needle through the bottom of the foot, so they go in through the top with a long, big ass needle. For me, they used a cryo spray that numb my toe a bit, there was definitely a pinch, but honestly not bad, I’d give it a 2/10 on a pain scale. For reference, I’d consider the ingrown nail a 2, and it jumps up to a 5 if you stubbed it. After the anesthesia, they roll a castration band over your toe to cut off the blood supply so it doesn’t squirt all over the place when they cut the nail. After a few minutes, they cut your nail straight back all the way to the nailbed, past the cuticle, then they use a chemical cauterizing agent on wooden stick to burn the nailbed to prevent regrowth stop bleeding, and sterilize the areas. After that, they remove the band, wrap your toe in gauze and give you your post op paperwork.
Post op instruction for me were to soak my toe twice a day in an epsom salt solution, and otherwise keep the area dry and clean. I had some bloody pus discharge from my toe the first time I changed the bandage, but it was clean after that.