a good thing to do is to start off the puppies with puppy milk formula (if the adult dog is not there) which is available at petsmart or petco and you can get a bottle made for puppies while getting the puppy formula,just hold the puppy and try to shove (gently) the bottle in their mouth eventually the puppies should start drinking the milk,and first start the puppies off with wet food rather than dry food,you could also mix the puppy formula with the wet puppy food.
It works really well to take dry food and soak it in water or pet formula and then mush it so it looks like a paste. At 5 wks the puppies should easily be able to eat it. Just remember when they learn to eat it can be quite messy! As they get used to it you can use less water and within a week they should be eating it dry.
Mixing dry puppy food (out of a bag) and wet puppy food (out of a can), smooshing it all together and making sure it's mixed VERY well... works for 4-6 week old pups.
We foster puppies all the time (we actually have 3 at our house at this very minute), and we tend to do the dry/wet/smoosh thing for the 4-10 week old's, and then transition them over to 100% dry (with a little wet thrown in every once and a while to make it interesting).
By 5-6 weeks, they should be pretty much weened off the bottle, so I'd stop that sooner rather than later, if I were you.
Just my 2 cents...