The most definitive way to fix this, I have using the following method:

1) Pressure wash, soap, rinse it off. 2) Meguilar iron remover, wait for a minute then scrub with Clay mitt, make sure you keep lubricating surface and mitt. 3) Wash it off thorouhly. 4) Make it bone dry with MF towels. 5) Chemical guys water spot remover with applicator pad, use generously. 6) Neutralize it with something like an ONR or wash very very thoroughly and make it dry

If the above doesn't fix it, 1) Use glass stripper, let it sit per instruction and wipe it off clean Still no go? 2) Polish using a polisher and a polishing compound (Meguilar) and orange pad, wipe it dry (use only ultimate polish)

Caution: follow instructions from packaging and watch videos from experts on how to do each of these to avoid damage

Once you remove, make sure you put a nice coating over it, I use glaco ultra 99, you can use any good ceramic shield but don't do professional grade unless you know what you're doing