That's a unique request. Usually we comment on what NOT to do in order to preserve the factory glass coating.
Dawn dish soap will do absolutely nothing, don't even try it. The factory coating is built into the make-up of the glass so you would have to mechanically and abrasively strip it with something.
Every manufacturer is different, I don't have any first hand knowledge on how deep into the glass the coating goes. It might be mixed into the entire glass structure or be a simple thin "top" layer that can be somewhat simply removed via machine or hand polishing with the right product. If the coating is mixed into the whole glass composition, than you're never going to get it off.
I have polished coated glass on numerous occasions to remove wiper trails and scratches on customer's cars with good success. The customer was fully aware that the polishing might remove the hydrophobic layer of the glass. Typically even a non glass specific polish should work like M205 or M100 with a coarse foam pad (my favorite one for glass is the coarse green foam Rupes pad). Depending on the scenario I might use Ceriglass polish or mix my own cerium oxide polish if I need something super aggressive to use with a rotary and glass specific pads (not recommended for beginners as this may cause permanent damage without proper care).
So my suggestion is try the least aggressive method possible as with all things. Try a mild polish like M205 with a foam cutting pad of your choice. If no results are produced, go to a more aggressive polish like M100. And if that doesn't work try Ceriglass. You can do away without a machine also it's just going to be very labor intensive and time consuming
Absolutely no sandpaper or scuff pads of any kind.
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