I put this in my command bar to change some parts to not cast a shadow.
local workplace = game.Workspace
for index,lights in pairs(workplace) do
if lights.Name == "Par1" then
lights.Arm.MeshPart.CastShadow = false
lights.Head.Base.CastShadow = false
lights.Head.Beam.CastShadow = false
lights.Head.FakeLens.CastShadow = false
lights.Head.Lens.CastShadow = false
end
end