How to care for hopeless baby birds?

There is a mud bird nest in the corner by our front door. There mother has flown away, and hasn't feed them for a while. We can't reach the nest, and 1 out of 4 birds fell out. We would really like to save them before they all fall out and die. We have been looking for bugs, and worms to feed them, but we can't get to the nest, or find food. We need some ed vice on how to care for them before they die. Please help by posting some answers for this question. We would like to find out what to do, so we can send our change to Disney's Friends Change. Thanks for your help!