How would I save leaderboard stats?

To elaborate, what I mean is how do I save the value/string/boolean of a "stat" within the leaderboard and to have it load the next the the character plays the game. An example of the script I'll be using so that you can edit it to get what I desire is the following:

game.Players.PlayerAdded:connect(function(plr)
local leaderstats = Instance.new("Model",plr)
leaderstats.Name = "leaderstats"

local lvl = Instance.new("IntValue", leaderstats)
lvl.Name = "Lvl"
lvl.Value = 1

local cash = Instance.new("IntValue", leaderstats)
cash.Name = "Gold"
cash.Value = 100
end)