Oh, I see that can't put them back because it isn't safe for them in your yard.
Okay, then... Here's what I found that worked the best. You should use a small long-tipped syringe with a tiny bottle nipple stuck over the end. (I bought a small animal nurser kit that contained multiple nipple shapes, and used the one that was long and thin.) Cut a small hole or cross-slits on the end so the milk can get out when you push gently to squeeze the milk into each bunnie's mouth. You must feed them goats' milk (which comes in cans at most pet stores) even though some people will tell you that kitten replacer is fine for rabbits. They are correct with regard to domestic rabbits, but they have different dietary needs than wild rabbits.
The milk will have to be fed to the babies warm, but not hot. I was able to easily nurse them by holding them securely in one hand that was held against my belly, while sqeezing the syringe with the other. Place the nipple close to the rabbit's mouth and maintain gentle pressure as long as you see it's mouth "chewing" and notice some milk bubbling around it's lips. If it stops drinking and lets the milk pour over its nose, it's probably full. Sometimes, it will take a bit to get the kits used to the taste of the goats' milk so you'll have to work on getting them to cooperate and accept the feedings at first. After a bit, it will get easier for all of you, though. After each feeding, you should notice a rounded belly so you will get to know when they've eaten enough. Feed them two to three times a day for the first two weeks or so. After that, you will be able to slowly start offering them some clover and grass from the yard.