C-Framing a Model instead of a brick?

So, I've got this script made, but it works only on bricks and not on models.

How would I change that so it works on models too?

movements=37
speed=0.2
for i=1,movements do
wait(0.01)
script.Parent.PLT.CFrame = script.Parent.PLT.CFrame + Vector3.new(0,-speed,0);
end

Thanks in advance!?