I start them off with a good quality canned kitten food. Make it kinda soupy (not too thin) and add in KMR milk replacer. Then only work with a teaspoon or two of the mixture (depending on the # of kittens). Put it on a paper plate and take each kitten one at a time. Put a tiny amount of the mixture on your finger and gently push it into their mouth a little - not too far, but enough for them to start licking and hopefully swallow.
You may need to do this several times. Then put the kitten by the plate and do the same thing....finger first gradually to the edge of the plate. If the kitten catches on, they will start eating.
I try about 3 times a day for the first couple of days. Within a week they all should be eating on their own. They WILL get quite messy, so feed on a washable surface and the kittens may need to be cleaned off after eating for a time or two.
Once they are eating the canned food pretty good, then I add some dry crunches on top till they are used to some hard food too.