How to remove glass scratches like this?
 

Hi guys, previous owner probably parked this under a tree for months so eventually hard sap must have solidified on the glass, then they probably used a terry cloth or rag with tons of force to get itmoff causing these marks. Whats the best way of getting it back to clear shape? Im afraid to do it by hand and polish but also afraid a rotary will create swirls everywhere..

They do make glass polishing compounds for removing fine scratches. Polishing glass can be quite tricky, and you can possibly do more harm than good. You can also use a dual action polisher, but achieving results can take a while. You also need to constantly apply water onto the glass surface area being polished, as well as the to polishing compound.

There is a product called Ceriglass. And, you would also need to use special rayon polishing pads like these.

I can pretty much guarantee you that a towel did not make those marks. Glass is much harder than clear coat and it takes much more to scratch it. If a windshield is exceptionally dirty, I'll start by using a razor blade to clean it then clay bar. Those scratches look like damage from a very abrasive tool. Sand paper possibly? Not sure why they would do that though.

Anyway, your best bet is to use a DA with a glass polishing pad and a glass polish. But to be honest, I doubt you'll be able to take those out without leaving the glass looking distorted.

It may take some time , but try repeat buffing with toothpaste.
On one of my old cars someone removed a sticker from the windscreen with a razor blade.
It took a loong time and a lot of toothpaste to buff out the scratches.

Looks to be on an edge, so probably slip from sanding while some body work was being done. Seen it before and I was told it would simply be easier to replace the glass.

100% not from a rag, glass doesn't scratch that way.

Those are deep. Looks like Scotch Brite.