"The strawberries are falling out easily."
Translation:Die Erdbeeren fallen leicht hinaus.
In this sort of context, "easily" = "leicht"; "simply" = "einfach".
"Die Erdbeeren fallen einfach hinaus" = you were trying to transport the strawberries in a net, but the holes of the net are too wide, so the strawberries simply/just fall out without the net holding them inside. This isn't about the likelihood of them falling out, it's just an emphasis.
"Die Erdbeeren fallen leicht hinaus" = it is easy for the strawberries to fall out; you've stacked a lot of boxes inside a trailer, with the strawberries on top, and if you go too fast, they're likely to fall off.
In other contexts, "einfach" and "leicht" can be used more or less interchangeably: "Die Aufgabe ist leicht/einfach" = "The task is easy/simple", although what you call an easy task ("leicht") isn't necessarily a simple ("einfach") one, maybe you're just very skilled.
If you mean "heraus":
"hinaus" means "moving out towards there" and "heraus" means "moving out towards here". For example, "Sie geht hinaus" = she's in the room with me and now she's leaving; "Sie kommt heraus" = I'm standing outside the house and she's coming out. You couldn't say "Sie geht heraus" or "Sie kommt hinaus".
In the case of the strawberries, the question is which point of view you're taking: "Sie fallen leicht hinaus" = your point of view / "position" is where the strawberries are (on a truck, in a bag, on a plate...), you're speaking from the strawberries' point of view: those that fall out fall away from where the strawberries are / should be.
"Sie fallen leicht heraus" = your "position" is outside of where the strawberries are, e.g. you're standing next to the truck and they might fall off there and towards you. (If you drive the truck, you'd use "hinaus".) With the bag and the plate, "heraus" works, because you, being a full-sized person, can only stand next to the bag/plate.
If you mean "raus", which is short for "heraus", you can use it not only instead of "heraus", but also instead of "hinaus" ("Sie geht raus."). (Don't use "raus" in formal writing.)