how do I weld one player's parts to another player's parts?

I need help trying to weld two parts of different players (their head and another one's head) I know welding is difficult with player to player connections but I can't figure anything else out. Anyone here that can help me? Also my script is just basic welding script (setting their part1 and part0's and parents but I'll post it anyway)

game.ReplicatedStorage.Moves.SPgrab.OnServerEvent:Connect(function(player)

    if player.Backpack:FindFirstChild("Grab") then
        local char = player.Character

        local hum = char.Humanoid

        local right = char:FindFirstChild("RightHand")

        local root = char:FindFirstChild("HumanoidRootPart")

        local grab = hum:LoadAnimation(game.ReplicatedStorage.Animations.SpecialMoveAnims.SPgrab)

        local punch = hum:LoadAnimation(game.ReplicatedStorage.Animations.SpecialMoveAnims.SPpunch)

        hum.WalkSpeed = 3

        if right then

            grab:Play()

            local fin = false

            wait(.1)

            right.Touched:Connect(function(hit)

                if hit.Parent:FindFirstChild("Humanoid") and fin == false then

                    if hit.Parent.Humanoid ~= hum then

                        local enhum = hit.Parent.Humanoid

                        local target = game.Players:FindFirstChild(hit.Parent.Name).Character

                        local instance = Instance.new("Weld")

                        instance.Part0 = right

                        instance.Part1 = hit.Parent.Head

                        instance.Parent = right

                        punch.Looped = true

                        punch:Play()

                    end
                end
            end)
        end
    end
end)