How do I use this script to display who won the minigame?

If you have a leaderboard script, where there is a value called 'Alive' or 'Winners' then you can do this.

-- List the players who are still alive and add them onto the winner's list.

local p = game.Players:GetPlayers()
local winners = {}

for i = 1, #p do 
	if p[i].leaderstats["Alive"].Value then
		print(p[i].Name.. ' is alive!')
		table.insert(winners, p[i].Name)
	end
end

Displaying the winner message.

-- Should be in the same script to get the winners.

local msg = "Winners are"

for j = 1, #winners do 
msg = (msg..", " ..winners[j])
end

local gm = Instance.new("Message")
gm.Parent = Workspace
gm.Text = msg
wait(5)
gm:Destroy()