I need help, Add the leaderboard when a player touches a coin?

I've been going around the internet how to add to a leaderboard! What I want to do is: when a player touches a coin, add to the "Coins" leaderboard, I've searched around the web, but all answers seem to be different!

I have the scripting for the coins done, and "Coins" is on the leaderboard, but I just don't know how to get it to go up! help!

Is there even a way to do so?
If not, should I just give up?

what I have is:

local cash = Instance.new("IntValue")
cash.Name = "Coins"
cash.Value = 0
cash.Parent = stats

And that works alright, I think.

The coins were not made by me. but, they get destroyed after you touch them.

What I've gathered together from the internet is:

workspace.Coin.CoinBoundingBox.Touched:connect(function(hit)
    cash.Value = cash.Value + 1
end)

And that doesn't work.

Any assistance would be greatly appreciated.

This is incorrect because if you do it server-side you need GetPlayerFromCharacter() to fetch the player. Example:

script.Parent.Touched:Connect(function()
	local plr = game.Players:GetPlayerFromCharacter(script.Parent)
	if plr then
		if plr:FindFirstChild("leaderstats", true) then
			local ls = plr:FindFirstChild("leaderstats", true)
			ls.cash.Value = ls.cash.Value + 1
		end
	end
end)

After a player touches this part they will have 1 more cash point.

This is a simple fix:

Now, I'm going to combine a leaderstats check in this, so remove that if needed.

					--[[
Single-Player API:
local plr = game.Players.LocalPlayer
local leaderstats = plr.leaderstats

-- Use a LocalScript (Client-Side)
					--]]


script.Parent.Touched:Connect(function(part)
	--[[
	Multiplayer API
	if game.Players:GetPlayerFromCharacter(part.Parent) then
		local plr = game.Players:GetPlayerFromCharacter(part.Parent)
	end

	-- use a plain Script (Server-Side)
	--]]

	if not leaderstats then
		leaderstats = Instance.new("Folder")
		leaderstats.Parent = plr
		leaderstats.Name = "leaderstats"
	end

	if leaderstats.Coins then
		local Coins = leaderstats.Coins
	else
		local Coins = Instance.new("IntValue")
		Coins.Name = "Coins"
		Coins.Parent = leaderstats
	end

	Coins.Value = Coins.Value + 1 -- or any amount you want really, especially if you have a system with pennies, dimes, and quarters etc.
end)

So one thing that I noticed you didn't include was most o your script. I only typed the portions that you requested, however I might not be completely sure that the script works with everything else you have smoothly, so tweak as needed.