How do you beat the target bonus for link. I've been trying for months..

As paper_boy says above, this is right. But when you jump, you may need to do Links double jump and Upwards round slash (Up + B) whilst in the air.

Stand on the platform to the left and throw your boomerang in the opposite direction to the target.

As it comes back, jump so it misses you and goes straight for the target.

Use your boomerang.

The boomerang method will work but is not the easiest way. The easiest is with a bomb. First get out a bomb (down b), then while standing directly under the target jump as high as you can with your two jump, don't up b. At the apex of your second jump do a hard up through of your bomb. This is similar to how you would do a smash while standing, you press up sharply and a at the same time.

To get the upper right target land on the upper most platform near it then use your boomerang. Using the boomerang effectively takes a little practice. To throw it farther press to the side you want sharply and b at the same time, the boomang will go much farther than if you just pressed b. Now, to direct it hold up or down while link is getting out the boomerang. When he throws it, the boomerang will go at an angle of up to about 30%