How do I help allies when they are stunned/asleep/paralyzed/etc?

Solution 1:

A small prefaction first: when a hunter is asleep or stunned, any hit will free them of that status; if a hunter is paralyzed, it takes a hit that sends the hunter flying, either horizontally or vertically. Since the kick doesn't send hunters flying unless when having the Felyne Kickboxer skill, it wasn't helpful against paralysis.

The special kick attack is gone from Monster Hunter World, and is now only part of the Greatsword's moveset. You can guard and press the Triangle/Y button to perform a kick.

Other than that, the same rules apply: in order to break an ally out of sleep and stun you only need to hit them with any weapon attack. If you want to save a hunter from paralysis, however, you'll need to use specific moves, such as:

• The Greatsword's rising slash
• The Hammer's charged uppercut
• The Gunlance's wyvern fire
• The Switch Axe's rising slash in axe mode
• Certain Bowgun ammo such as Wyvern Ammo, Sticky Ammo, and Cluster Ammo

I don't believe any weapon other than the ones mentioned can help a paralyzed ally with any move.