How to reduce credit amount when pickaxe is bought when server event is fired?

repStorage == game:GetService("ReplicatedStorage")
local remote = game.ReplicatedStorage.RemoteEvent	
local DSService = game:GetService("DataStoreService"):GetDataStore("CreditStorage")
game.Players.PlayerAdded:connect(function(plr)
	local uniquekey = "id-".. plr.userId
	local leaderstats = Instance.new("IntValue",plr)
	local savevalue = Instance.new("IntValue")
	leaderstats.Name = "leaderstats"
	savevalue.Parent = leaderstats
	savevalue.Name = "Credits"
	local GetSaved = DSService:GetAsync(uniquekey)
	if GetSaved then
		savevalue.Value = GetSaved [1]
	else
		local NumbersForSaving = {savevalue.Value}
		DSService:SetAsync(uniquekey,NumbersForSaving)
		
	end
end)

game.Players.PlayerRemoving:connect(function(plr)
	local uniquekey = "id-"..plr.userId
	local Savetable = {plr.leaderstats.Credits.Value}
	DSService:SetAsync(uniquekey,Savetable)
	remote.OnServerEvent(function(creditReduction)
	--What would I put here to reduce the credit amount? 
	end)
		
end)

Just having some problems. Not sure what I would put for the event. Help? My local script is in the button, and they will be talking to each other. I am trying to get the data storage to update when the button is pressed.