How to properly resize a model?

--[[Disclamer!!! BigBoiTiff is in production and is not allowed
	to be sold on the black market just yet ;). This is a work in progres
	so don't be mad if BigBoiTiff doesn't get as big as you want it to.
	This is a Harford Day School/Bennet Robinson Production! All Copyright
	Claims Belong to me! BigBoiTiff will be sold for 999999999 Kidneys
	When it is Released! Get your Kidneys ready becase it's coming out this
	Summer!
--]]



function BigBoiTiff()
	game.Workspace.Tiffany.Size = Vector3.new(999,999,999)
	
end

wait (8)

BigBoiTiff() --BigBoiTiff Activation

Tiffany is a r15 roblox female model and this script is supposed to make it super big, but it doesn't. Any help XD

It is a model and models do not have a size so, game.Workspace.Tiffany.Size = Vector3.new(999,999,999) does not do anything.

Under every humanoid in a Player has several values that can manipulate player HeadScale, BodyWidth, BodyDepth, and BodyHeight variables.

Read more here: http://wiki.roblox.com/index.php/API:Class/Humanoid

for _, v in pairs(game.Workspace.Tiffany:GetChildren()) do
    if v:IsA”BasePart” then
        v.Size = Vector3.new(X, Y, Z) — put your size
    end
end