On the fifth stage, the player have to deal with two kind of boxes, which he met on the previous stages.
The normal boxes and the IceBoxes which were first introduced on the fourth stage.
Step by step solution
From the initial position, push LEFT once.
Now go UP, UP and UP, then LEFT, then UP again.
Now push RIGHT, go UP and push RIGHT again.
Second box is placed correctly. From this position, push DOWN once, then go RIGHT, DOWN, DOWN, DOWN, DOWN and then LEFT.
The IceBox have a stopper, so it will not go away from where it should be. Push UP once, then go RIGHT and RIGHT and push UP.
The first IceBox is put properly. The second is easy to place - go LEFT once and push LEFT once.
From here only one box is left to be put. Push UP, then go RIGHT and UP. Now push LEFT and push LEFT again.
Congratulations. You have completed the fifth World. Get ready for the sixth.