How To remove scuff marks after ive had a case for long time

http://i.imgur.com/7tNTvFw.jpg

How to remove that ive tried:
Alcohol
Erase rubber
etc

Need an answer quick does anyone know how to remove this

 

Hi!
It looks like those marks are marks in the plastic body.
I don't see any other way to get rid of those other than to change the whole backside.

 

yea those look like marks on the body themselves.. I had scuff marks and tried alcohol and that worked for me.

 

What about Acetone?
I had to clean the screen on my electric bike the other day and the stains were mpossible to remove. Then I used a little bit of Acetone and rubbed it in and the screen looked like brand new after a couple of seconds.

 

Acetone will melt any unknown plastics and paint into a soggy mess, dont even think about it.