Easiest (but relatively slow) route: Use DB at the start for first two. Move next to the wall and Fsmash the right one (his head will go through the wall). Double jump to the platform, double jump to the next platform and Fair. Run off the platform and jump to the highest target and use Uair. Fastfall to the one straight beneath it and hit it with whatever. Double jump across the gap and UB one of the high-left targets, repeat to get the other one. Fsmash to hit the low left target. Double jump onto the moving platform, then double jump underneath and Uair the final target.

There are faster ways that require some more advanced techniques that are tough to pull off, but this'll complete it for now.