How do I access players in game.Players via server-sided script?

Here is a script that I have that adds a folder directory within players in game.Players. How do I access these values via a server-sided script that can edit those player-specific values? ex: Change the Class.Value of a specific player.

game.Players.PlayerAdded:connect(function(player)
	local folder = Instance.new("Folder")
	folder.Parent = player
	folder.Name = "Stats"
	--folder.Name = p.Name
	local Team= Instance.new("StringValue", folder)
	Team.Name = "Team"
	Team.Value = "No team"
	local Class = Instance.new("StringValue", folder)
	Class.Name = "Class"
	Class.Value = "No class"
	local Level = Instance.new("IntValue", folder)
	Level.Name = "Level"
	Level.Value = 1
end)

Ill show 2 examples. Through a LocalScript:

local plr = game.Players.LocalPlayer
wait(.25) --Wait so stats can be created
local Class = plr.leaderstats.Class --replace leaderstats with Stats
local UIS = game:GetService("UserInputService")

UIS.InputBegan:Connect(function(input,IsTyping)
	if IsTyping then return end
	
	if input.UserInputType == Enum.UserInputType.MouseButton1 then
		Class.Value = "Testing Class" --Whatever you want
	end
end)

Through .Touched:

local debounce = false
script.Parent.Touched:Connect(function(hit)
	if hit.Parent:FindFirstChild("Humanoid") then
		if debounce == false then
			local player = game.Players:GetPlayerFromCharacter(hit.Parent)
			local Level = player.leaderstats.Level --Replace leaderstats with Stats btw
			Level.Value += 1
			debounce = true
			wait(1)
			debounce = false
		end
	end
end)

Edit:Forgot he said server-sided please forgive me

You can edit them using Script, located at ServerScriptService.

game.Players:WaitForChild("ChirpPerson").Stats.Class.Value = "Thing"