How do you make a brick change it's rotation to the same as the object that hit it?

Try this, perhaps. This should take only the rotation of part h and apply it.

script.Parent.Parent.Touched:connect(function(h)
    local hCFrameRotationOnly = h.CFrame - h.CFrame.p
    script.Parent.Parent.CFrame =
        hCFrameRotationOnly + script.Parent.Parent.CFrame.p
end)

RightVector is a read-only value, and thus cannot be changed. Something like this might help instead:

script.Parent.Parent.Touched:Connect(function(h)
    local pos = script.Parent.Parent.Position
    local lookAt = pos + h.CFrame.lookVector
    script.Parent.Parent.CFrame = CFrame.new(pos,lookAt)
end)

Hey LennonLight,

The way that I am about to demonstrate before you is a pretty famous and easy way to change a part's direction that it faces. Well, I will show it to you below and explain it line by line. Better to demonstrate and explain at the same time rather than just say how to do it.

----Example----

local part = script.Parent; -- The part 
local parts_to_not_touch = { -- Dictionary with the names of the parts that it shouldn't react towards.
    ["Baseplate"] = true;
}

part.Touched:Connect(function(obj) -- Declares an anonymous function connected to a Touched event.
    if not parts_to_not_touch[obj.Name] then -- If statement checking if the obj's name isn't any stored in the table, so it can prevent reactions to those parts.
        part.CFrame = CFrame.new(part.Position, obj.Position); -- Changes the CFrame by keeping the part's original position and sets the direction that the part is facing to the object that it touched.
    end -- end for the if statement
end) -- end for the function

I hope that I helped, and have a nice day.

Thanks,

~~ KingLoneCat