How do I remove the reset abillity?

According to a ROBLOX Wiki article, there are two ways to remove the reset ability:

1. Change the name of the Humanoid to something other than Humanoid.

2. When the humanoid changes, change the player's health back to the default health and recreate the characters joints.

Method 1:

You will need to change the name of the Humanoid when the character is added. This can be done from a normal script. This method will actually stop the reset from working since ROBLOX can't find the humanoid.

game.Players.PlayerAdded:connect(function(plr) --Fires a function when a player is added, plr is the player that was added.
	plr.CharacterAdded:connect(function(char) --Fires a function when the player's character has spawned in or respawned, char is the character.
		char:WaitForChild("Humanoid").Name = "NotHumanoid" --Change the name of the humanoid.
	end)
end)

However, you will need to re-script certain parts of your game to accommodate the change of the Humanoid's name.

Method 2:

This is a more complex method, where the player does technically "die", but their reset is negated because their health is restored and their character doesn't fall apart.

game.Players.PlayerAdded:connect(function(plr) --Fires a function when a player is added, plr is the player that was added.
	plr.CharacterAdded:connect(function(char) --Fires a function when the player's character has spawned in or respawned, char is the character.
		char:WaitForChild("Humanoid").Died:connect(function() --Fires a function when the player dies.
			char.Humanoid.Health = char.Humanoid.MaxHealth --Set the health of the player to MaxHealth.
			char:MakeJoints() --Stops the character from falling apart.
	end)
end)

This method is less reliable than the first one since the player does die and it doesn't guarantee that the reset won't occur.

As stated by ROBLOX, you should not try to negate the reset ability. Instead, you should work around the reset ability, adapting your game to work even if someone resets their character.

I hope my answer has helped you. If it helped you, upvote it. If it solved the issue, be sure to accept it.