Yeah it's easy. The back springs can be tough to get back in, but they do go in.
The way I did it, put the whole thing together and do the springs last. Look at the springs and make sure to put them together correctly. Like springs that go in the same slot, they sandwich together a certain way. Then slide them in, squeeze them, and beat them in. So on the knife, slide the spring up to the knife pivot and that will push the knife out. Then push on the spring and squeeze the knife closed so there's tension on the spring. Then beat it on a piece of wood. Beat it down right on that spring like you're hammering a nail in with the end of a screwdriver. Keep squeezing the knife down while beating it and the spring will pop in. If it's your first time it will seem really hard, but the second time I did it was a lot easier because I knew it worked and wasn't afraid to beat it. The very last couple of taps, handle the thing so you hit right on the springs.