How do you make a map switch?

In a fighting game you know how the map changes? That is what I mean.

You put two or more different maps in game.ServerStorage and delete the map in Workspace and clone() a new map into workspace. Either..

Part by Part

local all=map:Clone()
local al=map:getChildren()
for a=1,#al do
al[a].Parent=Workspace.Map
wait()
end

or Whole

local all=map:Clone()
all.Parent=Workspace.Map