Note: The following is an user submitted guide by Grump.
I was workin' on my latest project today, scraping the edges of one of the acrylic panels on my case, when, whoops!, I scratched the glass.
This was especially disturbing, since it is the second attempt at this panel. At first, I didn't think the scratch went all the way to the acrylic -- isn't that why the protective paper is there? Well, a few minutes later, still scraping away at the edges, I did it again. Damn!

Well, I really wasn't looking forward to cutting another panel, so I tried a repair I'd heard about. Unfortunately, I didn't take any pictures of the repair in progress, but when I was done, I decided to purposely scratch a scrap of acrylic and show you how to fix it.
Below is my victim. The scratch was done with the same X-acto blade, but this one is much more severe. X marks the spot.

I took the paper off to reveal the extent of the damage.

Pretty nasty. Much worse than the original damage I did to my panel. My first step was to use dry 1000 grit sandpaper on it. I sanded in a circular pattern and tried to take as much of the scar out of the scratch.

Dry sanding made quick work of removing a thin layer of acrylic and the majority of the scratch. I then continued to sand with the same paper, only this time using water.

In this next picture, I have wet sanded with 1000 grit, drying and checking the progress often. You don't want to sand any more than necessary. I switched to 2000 grit wet sanding when the scratch was gone. This was to reduce the amount of abrasive swirls the 1000 grit paper produced.

With the acrylic piece looking smooth, but foggy from all that sandpaper, it was time to use the Novus 2 Fine Scratch Remover. This stuff WORKS! Of course, it could never take out as deep a scratches as I put in it, but it works wonders on very fine scratches. Apply it in a circular motion and work it in good.

Buff it out dry and polish. You can also use Novus 1 for polishing, but I'll let you see what it looks like after just the #2. The speckles and such are just lint.

My panel will look perfect when it's done. You can find the worklog HERE. I hope this How-To has helped you recover from a catastrophe.