How would i change a players name though a script?

    local commands = {}

    local admins = {
        "MAD_DENISDAILY2";
        "poopfartbarf1130";
    "Mickeyrus1";
    "andrust51";
    }

    local prefix = "/"

    local function findPlayer(name)

        for _, player in pairs(game.Players:GetPlayers()) do
            if string.lower(player.Name) == name then
                return player
            end
        end

        return nil

    end

    local function isAdmin(player)
        for _, v in pairs(admins) do
            if v == player.Name then
                return true
            end
        end

        return false
    end

    commands.tp = function (sender, arguments)

        print("TP Function fired by "..sender.Name)

        for _, playerName in pairs(arguments) do
            print(playerName)
        end

        local playerToTeleportName = arguments[1]
        local playerToTeleportName = arguments[2]

        if playerToTeleportName and playerToTeleportName then
            local plrToTP = findPlayer(playerToTeleportName)
            local plrToTPto = findPlayer(playerToTeleportName)

            if plrToTP and plrToTPto then
                plrToTP.Character.HumanoidRootPart.CFrame = plrToTPto.Character.HumanoidRootPart.CFrame
                print("Successfully moved!")
            end
        end

    end

    commands.speed = function(sender, arguments)

        print("Speed command fired by "..sender.Name)

        local playerToGiveSpeedTo = arguments[1]
        local amountOfSpeedToGive = arguments[2]

        if playerToGiveSpeedTo then
            local plr = findPlayer(playerToGiveSpeedTo)

            if plr then
                plr.Character.Humanoid.WalkSpeed = tonumber(amountOfSpeedToGive)
                print(playerToGiveSpeedTo.." was given Walkspeed "..amountOfSpeedToGive)
            end     
        end
    end

    commands.kill = function(sender, arguments)

        print("Kill command fired by "..sender.Name)

        local playerToKill = arguments[1]

        if playerToKill then
            local plr = findPlayer(playerToKill)

            if plr then
                plr.Character.Humanoid.Health = 0
                print(playerToKill.." was killed by "..sender.Name)
            end
        end
    end

commands.health = function(sender, arguments)

    print("Health command was fired by "..sender.Name)

    local playerToGiveHealthTo = arguments[1]
    local amountOfHealthToGive = arguments[2]

    if playerToGiveHealthTo then
        local plr = findPlayer(playerToGiveHealthTo)

        if plr then
            plr.Character.Humanoid.MaxHealth = tonumber(amountOfHealthToGive)
            plr.Character.Humanoid.Health = tonumber(amountOfHealthToGive)
            print(playerToGiveHealthTo.." was given "..amountOfHealthToGive)
        end
    end
end

commands.name = function(sender, arguments)

    print("Name command was fired by "..sender.Name)

    local playerToName = arguments[1]
    local nameToGive = arguments[2]

    if playerToName then
        local plr = findPlayer(playerToName)

        if plr then
            -- here i dont know how to
        end
    end
end

    game.Players.PlayerAdded:Connect(function(player)
        player.Chatted:Connect(function(message,recipient)
            if isAdmin(player) then
                message = string.lower(message)

                local splitString = message:split(" ")

                local slashCommand = splitString[1]

                local cmd = slashCommand:split(prefix)

                local cmdName = cmd[2]

                if commands[cmdName] then

                    local arguments = {}

                    for i = 2, #splitString, 1 do
                        table.insert(arguments,splitString[i])
                    end

                    commands[cmdName](player,arguments)

                    end


            end
        end)
    end)